Statistics Do Not Disprove Claim A-Rod Tipped Pitches

alex_rodriguez_150In her now infamous “A-Rod,” Selena Roberts alleges that Alex Rodriguez tipped pitches during blowouts while playing for Texas.  According to Dan Rosenheck of the New York Times, there is no evidence from statistics that Rodriguez tipped.  That is not necessarily true.

Rosenheck uses Tom Tango’s Leverage Index, which assigns a numerical value to an at bat given its importance to game outcome.  In Texas, Rodriguez hit better in high leverage situations (1.076 OPS) and medium leverage situations (1.017) than in low leverage ones (.982).  His middle infield opponents hit similarly (.899) in high leverage, (.825) in medium and (.817) in low.

Both A-Rod and his opponents hit worse in meaningless situations, leading Rosenheck to suggest there is no basis for Rodriguez tipping pitches in blowouts.

However, Rosenheck compiles statistics for all three seasons.  His assertions suggest Alex Rodriguez did not tip pitches ubiquitously to every middle infielder faced, in every blowout over every season in Texas.  That would be improbable anyway.

The large net of data masks a more likely isolated scenario, that Rodriguez had a relationship with a couple middle infielders.  These at bats would only have come in blowouts against those one or two teams, which could mean fewer than ten at bats per season.  This story would be swamped in Rosenheck’s large data pool.

A better method would be to divide the at bats in the low leverage situations by team to look for irregularities.  Unfortunately, this would not give enough examples to be statistically significant.

    • MK
    • May 17th, 2009

    “The large net of data masks a more likely isolated scenario, that Rodriguez had a relationship with a couple middle infielders.”

    Except that Michael Young and others have said this was not the case.

  1. Yes, because baseball players are known for their honesty about clubhouse matters…

    I’m not saying that Alex Rodriguez definitively was tipping pitches. What I’m saying is that that specific statistical analysis does not disprove it.

    • mike
    • May 18th, 2009

    if the whole thing was 10 at bats and the theory is he did it to pad his stats so how is he padding his stats with 10 at bats

    • OJ
    • May 18th, 2009

    If it was only isolated incidents where he tipped pitches or was tipped during a season, then what does it matter? You say in your column that it may have happened in only 10 of his at-bats per season. That’s not enough to even justify posting about.

  2. I think there is too much focus on the effect, when the ethical issue is the action.

    Say you cheat on one Geometry test. You probably would have passed the class without it. It didn’t affect your grade. It didn’t affect your GPA when you graduated high school. There’s no real effect, but it does not discount that cheating on a test was wrong.

    For sports, look at point shaving. It doesn’t matter if you only did it once and it didn’t affect the outcome of the game. It’s still point-shaving.

    The salient point is not padding his stats, it is whether it was sporting behavior or not. Maybe he tips pitches on a rare occasion in a blow out. But, that rare occasion could affect the last pitcher on the roster being sent down to the minors.

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