By Elliott Turner

Humans have always struggled to ascribe value to material objects. Arabic numerals helped greatly. So did the transition from a barter economy to the use of currency. These objective measuring sticks have assisted, even if we disagree about the specific worth of a particular item. Still, ambiguity clouds the exercise. Sport has embraced statistics as a lens to value players, but they mask some pretty subjective assumptions. The recent proliferation of the “key pass” stat in soccer analysis demonstrates this broader principle.

So, yawn, you already know about Moneyball: Baseball General Manager relies on new statistic to sign unheralded players, cure cancer, field competitive small-market team, and save Earth from impending destruction by an asteroid. Book published. Movie made. Brad Pitt plays G.M. G.M. gawks with approval. However, if Moneyball truly offered a silver bullet, then Billy Beane would have realized: “Shit, I kinda leaked the secret Coca Cola recipe. Now what?” It didn’t happen. And his A’s recently made the play-offs with a totally re-made roster. A Moneyball-unfriendly roster.

What most interests me about Moneyball are the non-statistical values that led to success. Like all small market G.M.s, Beane realized he couldn’t splash the cash on all-star sluggers. Instead, he made a value-based decision: find guys that get on base either through milking the count or singles. Thus, Beane made a philosophical and “tactical’ decision, then found the right stats to execute the game plan. For an example in soccer, let’s play counterfactual and look at Stoke City. Stoke can’t buy the Cristiano Ronaldos or Xavis of the world, so they make a decision to be tough-tackling and counterattacking. Philosophical underpinning: check. Then, let’s speculate that they invent or place great value to a nondescript stat: instead of tackles and interceptions per game (or miles ran per game), they look at heatmaps in away games. If a player has too much red too far away from his own box, he gets sold. Stats: check.

Offense in soccer, of course, presents a conundrum. Soccer is a game of scarcity: compared to the NBA, NHL, MLB, and even the NFL, little scoring occurs. Thus, the sport prizes goalscorers. Top strikers get sold for tens of millions of pounds/dollars/euros. Those players earn millions annually. However, coaches, pundits, and fans realize that strikers need “service,” ie, passes from teammates. In terms of statistics, this has led to credit for “assists”, which is the last pass before a goal. An assist includes both a run and cross that results in a headed goal, but also a slide-rule pass or lay-off. Soccer also has stats for “chances created.” This stat includes both a pass to a teammate that results in a shot on frame, but also a dribbling move that opens space for a player’s own shot. And, of course, soccer borrowed a page from the NHL and created the secondary assist statistic. This is for the second-to-last pass before a goal is scored.

As of publication, no secondary-chances created statistic exists. But what if it did? What if Andre Vilas-Boas has a secret way to keep track of “secondary-chances created”, a briefcase full of Excel spreadsheets with each pro player’s “second chances created” record, and this statistical edge explains his success at Porto and early success at Tottenham? Several years ago, when AC Milan’s somewhat older roster was winning the Serie A and Champions League, fans and pundits vaguely spoke of the “Milan lab” and a “jump test.” And this points to another problem with statistics: we often find an answer or solution, and then explain it via statistics. Not vice-versa.

The greatest example of this phenomena is the modern day obsession with “possession” and “passing.” The best teams for the last half-decade have been Barcelona and Spain. Guess how they win games? Tiki-taka. Short passes to feet. These teams experience success, so poets sing their praises. What do the analytically-minded do? Invent new numbers or add new weight to old statistics. The recent novelty is the “key pass,” a statistic similar to chances created. I say “similar” because nobody still knows exactly what a key pass is. At least until you see it. Some say it is a pass that leads to a goalscoring chance. Thus, it’s like an assist, but no goal. In terms of divine justice, this makes sense: nobody can blame Carrick if Welbeck flubs his through ball.

However, don’t “key passes” happen all over the field? Some would argue that the key to Barca’s game plan is the passing at the back, not the tip of the attack. Stats has always been stretched and used as post-hoc explanations, but “key pass” reaches and grasps to mask the great value judgment of our era: possession is king. Long live possession. Yet this just points to another great truth in all sports: copycat success. Why is possession great? Because Barcelona and Spain do it. Yet the chicken and egg must be sorted out: is Spain great because they possess the ball, or does possessing the ball make Spain great?

Moneyball offers no answer. For a few seasons, a G.M. made a tactical decision, and then used an ignored stat to poach some talent on the cheap. Don’t expect the “key pass” stat to allow your club to become the next Barca. Or even Stoke.

Elliott blogs about soccer at