Ruben Amaro Misunderstands At-Bats, Plate Appearances


PA = AB + BB + HBP + SH + SF + DI Mandatory Credit:

David Manning


I like to think that I’ve given Ruben Amaro a fair shake over the last few months. I liked almost all of his off-season moves.

Marlon Byrd‘s been worth his money. Carlos Ruiz has been consistent. A.J. Burnett was a great signing. Hell, despite the colossal crap-storm that has emerged presuming he’d be a bust, Jonathan Papelbon has been as advertised over his three seasons with the team.

The Brad Lincoln trade could be a quiet coup for the Phillies, if his recent Triple-A dominance as a starter transitions into major league production. He turned John McDonald into Nefi Ogando last season, a late-inning relief prospect who’s reported to hit 99 mph with his fastball. That’s brilliant.

I wrote A LOT about how he has a plan for the future, and is finally pointed in the right direction in terms of the farm system, free agent acquisitions, and the possibility of re-tooling the roster.

Basically, I’ve been more positive than almost anyone regarding the Phillies’ GM’s job performance over the last year.

However, what the crap.

During yesterday’s ballgame, Amaro joined Tom McCarthy and Jamie Moyer in the broadcast booth and spoke of Jimmy Rollins‘ impending franchise record-breaking hit, specifically how Rollins has actually accumulated those hits faster than the current record holder, Mike Schmidt.

"Yeah, we were checking it out. In fact, Schmitty was in the booth yesterday when we were talking about it, and I think it’s about a thousand difference in plate appearances. Pretty amazing. But their batting averages aren’t that different, which is kind of …weird. I don’t quite understand it."

Credit goes to Kyle Scott of Crossing Broad for picking up on this. I’ll admit, I had the game on in the background during this interview, only half listening, assumed he meant at-bats, but didn’t really think about why it was still weird.

The GM of a real-life, Major League Baseball team doesn’t understand that plate appearances include walks. This is no WAR, or UZR, or even FIP. This is plain, old plate appearances. I don’t want to just pile-on, but this is a basic one.

A plate appearance is what happens any time a batter completes their turn. This can be the result of a hit, an out, a walk, a hit by pitch, basically any normal baseball situation. An at-bat happens when a turn ends with either a hit, or an out (except for sacrifices) – these are the denominator for batting average. Walks and any other means of reaching base are discounted.

The apparent confusion in the quote comes from assuming that having the same number of hits in roughly 1,000 (894, to be exact) fewer plate appearances is a much higher frequency, and therefore would be a higher average. In reality, Rollins and Schmidt have almost identical batting averages (.268 vs .269).

The culprit? Batting averages don’t care how many walks you have, which is far and away the largest difference between ABs and PAs. In this case, a much larger number of Schmidt’s PAs ended in walks (1507) than Rollins’ (723).

Accordingly, Schmidt has a significantly higher career on-base percentage than Rollins (.380 vs. .328), but an almost equal number of ABs (8352 vs. 8320) despite playing for a longer period of time.

What do you get when you have almost exactly the same number of hits, divided by a very close number of at-bats? Almost the same exact batting average. Yeesh.