The CAS does not legislate: four decades of jurisprudence that prove the contrary (Part II)

Series: Lex Ludica and Lex Sportiva: the autonomous legal order of international sport
Technical level: High — arbitrators, sports lawyers, academics
Suggested citation: Martinez Cartagena, J.M. (2026). "The CAS says it does not legislate". The Sports Dossier. https://juanmanuelmartinezc.com/en/dossier/the-cas-does-not-legislate-four-decades-of-jurisprudence-that-prove-the-contrary-part-ii/

On December 4, 2009, the Court of Arbitration for Sport panel chaired by Michael Beloff QC issued the award in the case Tony Hansen v. FEI—a Norwegian rider who had won the bronze medal in equestrian jumping at Beijing 2008 and had lost it the following day due to the presence of capsaicin in his horse's urine. The award contains, in its fifth paragraph, one of the most explicit institutional statements that the CAS has produced regarding its own nature:

First, the CAS is a judicial, not a legislative body. It is not for the CAS to draft the FEI's regulations. As long as such regulations are not incompatible with some relevant aspect of public policy, whether competition law, human rights law, or Swiss legislation, we must apply them as they are. For us, only lex lata, not lex ferenda, is relevant.
CAS 2009/A/1768, Tony Hansen v. FEI, award of 4 December 2009, §21.3.^[1]

The statement is precise, conscious, and signed by one of the sports arbitrators with the greatest doctrinal influence of the last three decades, in my view. The CAS does not legislate. The CAS applies the law that exists, not the law that ought to exist. Only lex lata, not lex ferenda (referring to current law, not future law).

And yet: the principle of strict liability in doping matters, which that very award applies naturally as if it were universal customary law, was not codified in any state regulation when the CAS began to construct it in the 1990s. The criteria for calculating compensation for contract breach of professional football players, which today any sports lawyer cites as applicable law, were constructed by the CAS through the Webster and Matuzalem awards—without any federation having entrusted it with that function. The principle of proportionality of sanctions, which operates as a limit on the disciplinary power of federations throughout organized sport, was consolidated by the CAS case by case, award by award, without any regulatory text consecrating it with that scope.

The paradox is as follows: the CAS is right when it says it does not legislate, and the doctrine is right when it notes that the cumulative effect of its jurisprudence is functionally legislative. Both statements are true at the same time. Understanding why—and what practical consequences this tension has—is the subject of this second article of this Series in The Sports Dossier.

I. The vacuum that requires a rule-maker

The establishment of the CAS in 1984 responded to a structural need that state legal orders could not satisfy: transnational professional sport generated disputes between parties from multiple jurisdictions, on matters that national law did not regulate and with demands for rapid resolution that ordinary courts were incapable of providing. No state court could rule authoritatively on whether the FEI's anti-doping rules were compatible with international standards without entering into jurisdictional conflicts with the courts of other States. No national legislator could codify the criteria for compensation for breach of contract of a football player transferred from Brazil to Spain via Portugal without invading the regulatory competence of three different legal systems.

The creation of the CAS at the initiative of Juan Antonio Samaranch^[2] and under the normative impulse of Kéba Mbaye^[3]—IOC Vice-President and former judge of the International Court of Justice—was the institutional response to that vacuum. But the tribunal's original configuration suffered from a structural defect exposed by the Swiss Federal Tribunal's judgment of March 15, 1993^[4] in the case Gundel v. FEI: the close organic and financial ties with the IOC generated a well-founded risk of structural bias. The Paris reform of June 22, 1994^[5]—which created the International Council of Arbitration for Sport (ICAS) as an independent governance body and separated the CAS organically and financially from the IOC—was the enabling condition for the system that exists today.

Only after that reform could the CAS consolidate itself as the final adjudicative body of the international sports system with the institutional architecture necessary to produce jurisprudence with a universal scope. And it is precisely in this context—an independent tribunal with jurisdiction over the entirety of organized sport, resolving disputes for which there was no sufficient pre-existing law—where the cumulative normative effect of its jurisprudence is not only understandable but inevitable.

II. AEK Athens: the moment when the CAS became aware of its function

In August 1999, in rendering the award in AEK Athens & SK Slavia Praha v. UEFA (CAS 98/200)^[6], the CAS panel did something that no previous panel had done with the same explicitness: it articulated a catalog of general principles of sports law intended for systemic application, invoking a direct analogy with the lex mercatoria of international commerce. It did not merely resolve the specific case—the validity of the UEFA rule on competition integrity in situations of joint ownership of clubs—but took the opportunity to declare that there existed a body of unwritten, universally applicable principles to which international sports federations had to submit, independently of their own internal regulations or the applicable national law.

We cannot fail to mention Dr. Matthieu Reeb, Director General of the CAS, who recognized retrospectively in the introduction to the second volume of the Digest of CAS Awards^[7] that the first volume—which compiled the awards from 1986 to 1998—had already documented the formation of a lex sportiva through the tribunal's accumulated arbitral practice. With this statement, Reeb was not describing a phenomenon external to the CAS. He was recognizing that the tribunal itself had been constructing rules—principles, standards, criteria of interpretation—from its first years of operation, without any regulatory text expressly tasking it with that function.

AEK Athens is, in this sense, the moment of normative self-awareness of the system: the first award in which the CAS explicitly and deliberately assumes that it is contributing to an autonomous body of case law, not simply resolving isolated disputes. And this self-awareness is what transforms the accumulation of previous awards—each technically limited to its specific case—into the starting point of a legal order.

III. Contractual stability: how a principle of lex sportiva is built - award by award

The most illustrative case of the normative effect of CAS jurisprudence—and the one that best demonstrates the tension between the tribunal's formal self-description and its actual function—is the construction of the doctrine of contractual stability in professional football.

Article 17 of the FIFA Regulations on the Status and Transfer of Players (RSTP) establishes the consequences of the unilateral breach of a sports employment contract without just cause. The text of the rule is relatively brief and, regarding the calculation of compensation, deliberately open: it lists criteria without prioritizing them or establishing a methodology. This openness was not an oversight by the lawmaker—in this case, FIFA—but was simply left to the discretion of the adjudicator, initially FIFA's own decision-making bodies, who determined the application of those criteria.

However, it was the CAS itself that illustrated, in each case, how the criteria of this federative provision should be applied. The Webster award (CAS 2007/A/1298 & 1299)^[8] was the first major attempt at this construction. The panel interpreted Article 17 in a restrictive sense, limiting the compensation owed by the contract-breaking player to the residual value of the agreed-upon salary for the unfulfilled period—without taking into account the player's market value or the economic impact of the transfer on the club. The decision was criticized by clubs as excessively favorable to the player and destabilizing to the system. FIFA did not amend the RSTP after Webster, but the doctrinal and practical pressure on the interpretation of Article 17 was intense.

The Matuzalem award (CAS 2008/A/1519 & 1520)^[9] reformulated the approach with greater sophistication. The panel rejected the restrictive reading of Webster and developed a multi-factor methodology that weighed the player's market value, the fees paid by the new club, the remaining contract time, the economic situation of the parties, and other relevant elements of the specific case. The Matuzalem formula became, since then, the standard reference that all CAS panels apply when interpreting Article 17—with adjustments and nuances, but with a methodological consistency that no previous regulatory text required.

What this process reveals is the exact mechanics of the CAS's normative function: the tribunal did not write Article 17 of the RSTP. But it created the only interpretation of Article 17 that the system recognizes as authoritative. The difference between writing a rule and creating its only recognized interpretation is formally real. Practically, it is irrelevant.

IV. Strict liability: the rule that the CAS universalized before anyone codified it

Strict liability in doping matters was not born in any national code or in any international treaty. It was born in CAS jurisprudence—but its genesis is more complex than simple consecration: it is the product of a tension between the principle that the tribunal wanted to apply and the conditions it demanded in order to apply it.

The foundational award is CAS 94/129, USA Shooting & Q. v. Union Internationale de Tir (UIT)^[10], issued in 1995 by a panel chaired by Jan Paulsson. The case involved an American shooter who had ingested a medication prescribed by the team doctor during a competition in Cairo, unaware that it contained a prohibited substance. The panel sympathized with the strict liability principle—and stated so clearly—but refused to apply it because the UIT regulations did not establish it with sufficient precision. The reason given by the tribunal is what makes this award foundational:

"The fight against doping is a difficult one and may require strict rules. However, those who draw up and apply the rules must first be strict with themselves. Regulations that can affect the career of dedicated athletes must be predictable. They must emanate from properly authorized bodies. They must be adopted in a constitutionally correct manner. They must not be the product of a diffuse process of accumulation. Athletes and officials must not be confronted with a tangle of rules that complement each other, or even contradict each other, and that can only be understood from de facto practice, over many years, by a small group of people with inside information."
CAS 94/129, USA Shooting & Q. / Union Internationale de Tir (UIT), §34.^[11]

The paradox is revealing: the CAS did not consecrate strict liability in CAS 94/129. It consecrated the conditions that any rule must meet in order to be legitimately applied. These conditions—predictability, origin in properly authorized bodies, adoption through constitutionally correct procedures—are simultaneously the standard that the tribunal imposes on federations and the strongest argument in favor of the internal coherence of arbitral jurisprudence itself. The irony is that this warning describes exactly the risk that the CAS's accumulated jurisprudence could embody if rigorous systematization did not exist. But the CAS did not read it as self-criticism: it read it as a standard of requirement that the tribunal itself had to impose on federations—and that it had to fulfill itself.

The federations learned the lesson separately. A unified code did not yet exist—the WADA World Anti-Doping Code would not enter into force until 2003—but several international federations gradually incorporated strict liability into their own regulations, each with its own wording, responding to the standard set by CAS 94/129. It is precisely this regulatory fragmentation that makes the CAS's function more significant: it was the tribunal, not the lawmaker, who built the system's coherence by applying the same principle to different regulations from different federations, eventually consolidating it as consistent jurisprudence.

By 1999, when the CAS issued the award CAS 98/214, B. v. Fédération Internationale de Judo (FIJ)^[12], this consolidation process was already visible. In that award, the panel applied strict liability, describing it in those terms—"consistent jurisprudence of the CAS", a literal expression appearing in §3 of the award—and articulated it with structural precision: the presence of a prohibited substance in the athlete's body has two distinct consequences. The first is disqualification from the competition, which operates on the basis of sporting fairness toward the other participants, independently of any subjective element. The second is a presumption of fault that the athlete can attempt to rebut. The distinction between both consequences—one absolutely objective, the other shiftable—is the architecture upon which the international anti-doping system operates to this day, including the World Anti-Doping Code in all its versions since 2003.

By 2009, when Beloff QC drafted the award CAS 2009/A/1768^[13] in Hansen v. FEI, strict liability was already consolidated customary law: the panel applied it by citing CAS 95/41 and CAS 2005/A/829 as part of a line of jurisprudence that does not need to be justified anew in each case. When the defense questioned its compatibility with Swiss law, the tribunal responded that the Swiss Federal Tribunal had already validated it in ATF 134 III 193^[14]—meaning that Swiss law had validated the standard constructed by the CAS, not the other way around—and that it was also compatible with the European Convention on Human Rights, as the ECtHR had admitted in Salabiaku v. France^[15] (application no. 10519/83) that strict liability can be compatible with the right to a fair trial.

The CAS built the rule federation by federation, before a unifying code existed. The World Anti-Doping Code codified it in 2003. The Swiss Federal Tribunal validated it. The ECtHR declared it compatible with fundamental procedural guarantees. If that is not a normative function, the difference from a normative function is too fine to have practical consequences.

V. Precedent without stare decisis: how a system works without the rule that defines it

The CAS is not formally bound by its own precedents. The Code of Sports-related Arbitration contains no provision consecrating stare decisis—no panel is bound by the award of a previous panel, and each arbitral panel is, in principle, free to depart from any previous decision. The CAS itself has recognized this clearly: in the award IAAF v. USA Track & Field and Jerome Young (CAS 2004/A/628, §73), the panel formulated the tension with surgical precision:^[16]

"As has been demonstrated, much of the debate before the Panel revolved around the effect of the First CAS Decision. The Panel had to examine in detail both the issues raised before the First CAS Panel and the terms of that Decision. In CAS jurisprudence, there is no principle of binding precedent or stare decisis. However, a CAS Panel will attempt, if the evidence permits, to reach the same legal conclusion as a previous Panel. Whether this is considered a matter of international comity or an attempt to build a coherent body of law is irrelevant."

For the panel, the distinction between collegiate deference and the attempt to build a coherent body of law yields the same result. For the doctrine, it does not. Professor Gabrielle Kaufmann-Kohler^[17] examined this distinction with empirical rigor in her 2007 study—Arbitral Precedent: Dream, Necessity or Excuse?^[18]—and documented a detail that changes the analysis: before 2003, only one in six CAS awards cited previous cases; after 2003, practically all of them do. Her conclusion was direct: the data demonstrate the existence of a true de facto stare decisis in sports arbitration. Not a system that functions as if it had binding precedent—a system that in practice has binding precedent, regardless of what its procedural code says.

What this mechanism produces is precisely what legal theory recognizes as a constitutive element of a legal order: internal coherence, predictability, and the accumulation of interpretative criteria that the users of the system can anticipate and upon which they can plan their conduct. The CAS formally has neither a lawmaker nor a rule of precedent. But it has something functionally equivalent to both—and, according to Kaufmann-Kohler, in the case of precedent, not only functionally equivalent but substantially identical.

VI. The denial revisited: lex lata, lex ferenda, and what the distinction fails to capture

Let us return to the Tony Hansen v. FEI award. The distinction that Beloff QC draws between lex lata and lex ferenda is genuine and has real legal content. The CAS cannot—and in the vast majority of cases does not attempt to—substitute itself for the federative lawmaker to write the rules it believes should exist. When the panel in Hansen declares that it cannot rule on whether the detection threshold for capsaicin—the active compound of chili pepper used as a topical stimulant on horses' legs to hypersensitize them to obstacles—established by the FEI was technically correct, or whether the federation should have set different technical standards, it is exercising an abstention that corresponds exactly to the distinction between applying existing law and creating desired law. Capsaicin was listed and prohibited: what the CAS refuses to do is redesign the technical parameters that the federation has sovereignly established.

But the lex lata / lex ferenda distinction does not capture the phenomenon this article describes. What the CAS does—what it has done for four decades—is not to write new rules. It is to create the interpretative matrix within which all rules must be read. That matrix—the principles of contractual stability, proportionality of sanctions, strict liability, protection of minors, fair play—is none of the rules that the CAS applies. It is the condition of possibility for any correct application of those rules within the system.

The difference is not abstract. A panel that applies Article 17 of the RSTP without knowing the Webster-Matuzalem doctrine is not incorrectly applying the text of the rule: it is ignoring the only authoritative interpretation recognized by the system. A panel that imposes a disciplinary sanction without weighing the principle of proportionality as the CAS has jurisprudentially constructed it is not violating any article of any regulation: it is producing an outcome that the system will reject in the next instance. The difference between regulatory text and interpretative matrix is the difference between the letter of the law and living law. And the CAS is the builder of the living law of international sport.

This function—building the interpretative matrix, not writing the rules—is precisely what makes the CAS's self-description in Hansen simultaneously correct and insufficient. Correct: the CAS does not write Article 17 of the RSTP. Insufficient: without the Webster-Matuzalem doctrine built by the CAS, Article 17 of the RSTP has no defined operational content. The federative lawmaker wrote the text. The CAS made it law.

This function is neither an accident nor an usurpation. It is the inevitable consequence of a tribunal operating in a regulatory vacuum that States have not filled and that federations have filled only partially. When the text is incomplete—and Article 17 of the RSTP was—someone has to complete it. In the international sports system, that someone is the CAS. Not because it decided to be, but because it is the only one that can.

The CAS is right when it says it does not legislate. The doctrine is right when it notes that its jurisprudence has a legislative effect. This tension is not a contradiction that needs to be resolved: it is the structural condition of a private tribunal adjudicating in a vacuum. Kaufmann-Kohler called it de facto stare decisis. The panel in Hansen called it comity—collegiate deference among arbitrators—and said the distinction did not matter. For those who litigate in the system, it matters: because on it depends whether the precedent they cite operates as persuasive authority or as applicable law. In CAS practice, after 2003 and with the citation frequency documented by the data, the difference is increasingly difficult to maintain.

The next article in this series will examine the moment when this accumulated normative effect collided head-on with the legal order of the European Union—and what Bosman, Meca-Medina, Diarra, and Seraing reveal about the real limits of the functional autonomy of lex sportiva.

Jurisprudential references

• CAS 94/129, USA Shooting & Q. v. Union Internationale de Tir (UIT), award of 23 May 1995 (Panel: Paulsson, Oswald, Argand).
• CAS 98/200, AEK Athens & SK Slavia Praha v. UEFA, award of 20 August 1999.
• CAS 98/214, B. v. Fédération Internationale de Judo (FIJ), award of 17 March 1999 (Panel: Rasquin, Ndiaye, Oswald).
• CAS 2004/A/628, IAAF v. USA Track & Field and Jerome Young, award of 28 June 2004, §73.^[19]
• CAS 2007/A/1298 & 1299, Webster v. Heart of Midlothian FC & SFA, award of 30 January 2008.
• CAS 2008/A/1519 & 1520, Matuzalem & Real Zaragoza SAD v. Shakhtar Donetsk & FIFA, award of 19 May 2009.
• CAS 2009/A/1768, Tony Hansen v. Fédération Équestre Internationale (FEI), award of 4 December 2009 (Panel: Beloff QC, Hobér, Geistlinger).
• CAS 95/41, cited in CAS 2009/A/1768, §21 [parties not verified in primary source].
• Swiss Federal Tribunal, judgment of March 15, 1993, Gundel v. Fédération Équestre Internationale—foundational case of the 1994 CAS institutional reform.
• Swiss Federal Tribunal, ATF 134 III 193 (5C.248/2006)—compatibility of strict liability with Swiss law, cited in CAS 2009/A/1768, §21.
• ECtHR, Salabiaku v. France, judgment of 7 October 1988, application no. 10519/83—compatibility of strict liability with Article 6 of the ECHR.
• Swiss Federal Tribunal, judgment of May 27, 2003, Lazutina & Danilova—confirmation of the institutional independence of the CAS following the 1994 reform.

Doctrinal references

• Romano, S. (1918). L'ordinamento giuridico. Sansoni (reprint 1946).
• Giannini, M.S. (1949). "Prime osservazioni sugli ordinamenti giuridici sportivi". Rivista di Diritto Sportivo, vol. 1.
• Reeb, M. (ed.) (2002). Digest of CAS Awards II, 1998–2000. Kluwer Law International. [Introduction: genesis of the concept of lex sportiva.]
• Foster, K. (2005). "Lex Sportiva and Lex Ludica: The Court of Arbitration for Sport's Jurisprudence". Entertainment and Sports Law Journal, vol. 3, no. 2.
• Kaufmann-Kohler, G. (2007). "Arbitral Precedent: Dream, Necessity or Excuse? The 2006 Freshfields Lecture". Arbitration International, vol. 23, no. 3, pp. 357–378.
• Latty, F. (2007). La lex sportiva: Recherche sur le droit transnational. Martinus Nijhoff Publishers.
• Nafziger, J.A.R. (2004). International Sports Law (2nd ed.). Transnational Publishers.
• Casini, L. (2011). "The Making of a Lex Sportiva by the Court of Arbitration for Sport". German Law Journal, vol. 12, no. 5, pp. 1317–1340.^[20]

1. CAS 2009/A/1768, Tony Hansen v. FEI, award of 4 December 2009, §21.3. ↩︎
2. Samaranch, J.A. Founded the CAS at the initiative of the IOC in 1984. See Reeb, M. (ed.) (1998). Digest of CAS Awards I, 1986–1998. Staempfli. [Introduction.] ↩︎
3. Mbaye, K. See Latty, F. (2007). La lex sportiva: Recherche sur le droit transnational. Martinus Nijhoff Publishers, p. 37. ↩︎
4. Swiss Federal Tribunal, judgment of March 15, 1993, Gundel v. Fédération Équestre Internationale—foundational case of the 1994 CAS institutional reform. ↩︎
5. Paris Reform of June 22, 1994: creation of the International Council of Arbitration for Sport (ICAS). See Reeb (n 2), [Introduction]. ↩︎
6. CAS 98/200, AEK Athens & SK Slavia Praha v. UEFA, award of 20 August 1999. ↩︎
7. Reeb, M. (ed.) (2002). Digest of CAS Awards II, 1998–2000. Kluwer Law International. [Introduction: genesis of the concept of lex sportiva.] ↩︎
8. CAS 2007/A/1298 & 1299, Webster v. Heart of Midlothian FC & SFA, award of 30 January 2008. ↩︎
9. CAS 2008/A/1519 & 1520, Matuzalem & Real Zaragoza SAD v. Shakhtar Donetsk & FIFA, award of 19 May 2009. ↩︎
10. CAS 94/129, USA Shooting & Q. v. Union Internationale de Tir (UIT), award of 23 May 1995 (Panel: Paulsson, Oswald, Argand). ↩︎
11. Ibid, §34. ↩︎
12. CAS 98/214, B. v. Fédération Internationale de Judo (FIJ), award of 17 March 1999 (Panel: Rasquin, Ndiaye, Oswald). ↩︎
13. CAS 2009/A/1768 (n 1), §21. ↩︎
14. Swiss Federal Tribunal, ATF 134 III 193 (5C.248/2006)—compatibility of the strict liability principle with Swiss law. ↩︎
15. ECtHR, Salabiaku v. France, judgment of 7 October 1988, application no. 10519/83—compatibility of strict liability with Article 6 of the ECHR. ↩︎
16. CAS 2004/A/628, IAAF v. USA Track & Field and Jerome Young, award of 28 June 2004. ↩︎
17. Kaufmann-Kohler, G. (2007). ‘Arbitral Precedent: Dream, Necessity or Excuse? The 2006 Freshfields Lecture’. Arbitration International, vol. 23, no. 3, pp. 357–378. ↩︎
18. Ibid. ↩︎
19. Ibid, §73. ↩︎
20. Casini, L. (2011). ‘The Making of a Lex Sportiva by the Court of Arbitration for Sport’. German Law Journal, vol. 12, no. 5, pp. 1317–1340. ↩︎