Mike Ohlman and the Passed Ball Dilemma

Just about anyone reading FanGraphs probably knows about the debate surrounding defensive statistics. About the only thing everyone seems to agree on is that all defensive statistics are inadequate reflections of defense, or at least need extremely large sample sizes to attain reliability. This is especially true with regard to catchers, whose defensive contributions are quite the riddle to solve.

These issues extend even more in the minor leagues, where the sole widely available statistics are the traditional ones–assists, putouts, errors, double plays, range factor, and fielding percentage. Needless to say, these are not broadly effective arbiters of defensive aptitude. Again, catcher defense is arguably even more elusive, with passed balls and caught-stealing percentage the only remotely notable metrics. The desperate search to link numbers to potential leads these stats to often stand for “receiving skills” and “throwing arm,” respectively, which is a gross overstatement of their utility.

In this post, I want to examine just how meaningful, or perhaps meaningless, the passed ball statistic is for catching prospects.

Baltimore catching prospect Mike Ohlman is a good example. Ohlman is a catcher, or perhaps a “catcher,” who hit .313/.410/.524 in High-A Frederick this year. He was just 22, so he wasn’t too old for the level, his 93/56 K/BB checks out, and though he hit in a very friendly home park, he still managed an excellent .290/.374/.464 mark on the road in a generally pitcher-friendly league.

I’ve seen Ohlman live, and he’s not just some unbalanced hitter beating up on inexperienced pitchers. Check out this swing:

Three things:

1.) Mike Ohlman is big.
2.) Mike Ohlman is strong.
3.) Despite the clear truth of the above statements, Ohlman doesn’t sell out for power, utilizing a fairly balanced medium-length stroke with a lot of natural leverage.

Ohlman’s relatively sound hitting mechanics, natural power, and solid plate discipline give him a chance to hit something like .265/.340/.455 in the big leagues in a few years, which would put him in the .345 wOBA range. That would place him in the upper third of MLB catchers (who hit a combined .245/.310/.388 in 2013) but would be fairly pedestrian at first base, the only other position Ohlman has a chance of playing (1Bs hit .261/.337/.436 in 2013).

Ohlman could hit enough to be useful at either spot (or DH) if he meets his upside, but the former 11th-rounder would be a much bigger find if he could stick behind the plate. Unfortunately, I can’t offer much personally on his defensive capability as a catcher, because I only saw him in the lineup as a designated hitter. I can, however, offer up a few basic facts about his defense.

1.) At 6’4″, he’s a dreaded “tall catcher.”
2.) He caught 46 times and DHed 53 in 2013, even though the other catchers on his team were 26-year-old indy ball signee Zane Chavez (45 starts) and 25-year-old journeyman Allan de San Miguel (50 starts); he also only caught in 14 of his 71 games played in 2012.
3.) In his 46 games caught this year, Ohlman allowed eight passed balls while catching 22 of 77 (29%) attempted basestealers. For his career, he’s allowed 41 passed balls in 195 games and caught 27% of base thieves.

This trio of facts doesn’t exactly paint the most optimistic picture regarding Ohlman’s future behind the plate. The scouting bias against tall catchers doesn’t help him, his inability to push aside two veterans in High-A says something about where the Orioles view his defense, and eight passed balls in 46 games caught would work out to 24 miscues in 138 contests, roughly a full season of everyday catching. By comparison, current Orioles catcher Matt Wieters has 16 career passed balls in 618 games caught; Ohlman allows pitches to get by him approximately six times as often.

Those numbers seem grim, but we need context. For one, in 2013, High-A catchers allowed 517 passed balls whereas MLB backstops permitted just 318, a split that’s even more pronounced when one considers that High-A teams played a 140-game schedule. Part of the reason for the elevated passed ball rate is that High-A catchers aren’t as talented as MLB ones, of course, but another part is that they simply have less experience, in much the same way that error rates of infielders tend to improve as they progress from their teenage years to their primes.

We can debate how relevant passed ball totals are to the quality of a major league catcher’s defense, but that’s a separate discussion. What is undeniably true, however, is that passed ball rates like those of Ohlman and many other low-minors catchers are never seen in MLB unless knuckleball pitching is involved–J.P. Arencibia led MLB with 13 in 131 contests this past season. The minimization of passed balls may not say much about a catcher’s framing skill or his ability to handle a pitching staff, but it does seem that they have to be quite infrequent for a catcher to be deemed worthy of sticking behind the plate in a major league uniform.

We need a way of measuring this standard, and I’m going to proceed using the quite crude measure of passed balls per game caught. In a perfect world, one would measure passed ball frequency by (passed balls/number of non-wild pitches that were not contacted by the batter), but we obviously don’t have that data for minor league catchers–in fact, there’s not even innings caught data for them. Games caught data obviously comes with issues–it counts catching an inning as a defensive replacement as equal to catching a 17-inning marathon–but it’s broadly functional, and the best (really only) thing to work with from the available data.

For some perspective on what is “normal” for the statistic, I looked at MLB data for the last several years and found that the average MLB rate is approximately .065 passed balls per game caught, or around one passed ball for every 15 contests, with the threshold of “passable” and “problematic” being somewhere around .1 per game.

Obviously, many minor league catchers are far above this threshold. San Diego’s Austin Hedges is touted as perhaps the best defensive catcher in the minors, but he allowed 16 passed balls in 94 games in 2012 (.17 per game), cutting down to 7 in 79 (.089 per game) this year. Texas’ Jorge Alfaro, another highly touted backstop, committed 26 miscues in 82 contests (.317 per game). There are plenty of other examples.

So the question is, do numbers like these mean anything? Do nightmarish passed ball totals foreshadow defensive inadequacy, or does almost everyone eradicate the issue with experience? Let’s look.

To obtain a sample, I looked at all catchers who were 22 between 2003 and 2007 and caught at least 50 games (at any level) in their age-22 season. Age 22 works well because it a) includes college draftees and not just high schoolers and international signees, b) most fairly talented players are in full-season ball by age 22, and c) it is still fairly representative of a somewhat nascent developmental stage. There were 131 such players, and their passed ball rates at age 22 ranged from Jose Reyes‘ mere 1 in 91 contests (.011 per game) to Lucas May’s 31 in 78 games caught (.397 per game). The average age-22 passed ball rate was .149 per game, slightly more than double the MLB rate.

I wanted to see where the passed ball rates of these players ended up when they were essentially “finished developing.” Age 27 is the most common “peak year” for position players, followed by age 26 and 28, so for the sake of increasing the sample size of the metric, I decided to compare the age-22 passed ball rates of the catchers in the sample to their passed ball rates over their age 26-28 seasons. If a player hasn’t figured out how to curb the miscues at that age, he’ll likely never turn the corner.

Of course, not all 131 catchers in the sample managed to stay in organized baseball through their age-28 seasons. Two never played again;,11 played just one more season, 19 others didn’t make it past age 24, eight were finished at 25, eight more at 26, and seven more at 27. Mike Jacobs was moved to first base, Tyler Parker and Phil Avlas were moved to the outfield, and Jake Fox, Matt McBride, and Max Ramirez were largely moved, seeing only spot duty at catcher by their late twenties. Eight others were moved to the mound, leaving 62 of the 131 (47.33%) as still-employed catchers in affiliated ball at age 28.

First, then, I wanted to see if age-22 passed ball rate had anything to do with who was still catching in organized ball six years later. The catchers who didn’t make it average .154 passed balls per game at age 22, whereas those that did averaged .144. That’s a slight difference that probably doesn’t mean anything, and for the catchers who were done by age 27, age-22 passed balls per game had no correlation with the last year they played. Heck, Reyes and his tremendous rate were done at 24, while May’s survived behind the plate through the 2013 season.

That in itself doesn’t mean age-22 passed balls mean nothing; the ability to hit is obviously paramount, not to mention the other aspects of the catcher position defensively, and a catcher’s ability in these other areas likely plays a far bigger role in his longevity than passed ball numbers. But what of those age 26-28 passed ball rates for the 62 catchers who did stick around through their hypothetical primes?

That’s age-22 passed balls per game on the horizontal axis, with age 26-28 ones on the vertical axis. Let’s note a few things here.

First off, every single catcher in the sample got their passed ball rate down to less than .16 per game in their age 26-28 years, the worst being Steve Lerud’s .158 (the best was J.R. Towles‘ .02). Twenty-two of the 62 (35.48%) were at .16 or higher at age 22, and all of them improved to get below that threshold. Thus, we can call .16 a rough “floor” of sorts for experienced catchers. These .2 and .3 numbers that we see in the low minors are almost guaranteed to vanish, and if they don’t, the player likely will be cut or moved elsewhere on the diamond. Ohlman has a .21 career rate and was at .173 this past season; if he’s still around in six years, he’s virtually guaranteed to have taken at least a small chunk out of that number.

Second, there is a correlation. Lerud had the second-worst passed ball rate of any age-22 catcher and ended up with the worst rate at 26-28; May had the worst rate at 22 and the fourth-worst at 26-28. The best age-22 rate was put up by Brian McCann, who ended up well above-average (.048) in his prime; Towles, likewise, already had an MLB-average passed ball rate (.065) at 22. The r^2 of .1376 indicates a correlation, though not a particularly strong one.

And that leads me to my final point–while there is a general trend here, there is certainly the potential for catchers with poor passed ball rates at 22 to be relatively problem-free in that regard in their primes. Brad Davis allowed 15 passed balls in 59 games caught (.254 per game) at 22, but just 11 in 294 games caught (.037) from age 26-28. Chris Snyder went from .257 to .072, Wyatt Toregas from .286 to .088, Kris Watts from .212 to .058, Brett Hayes from .197 to .056, Nevin Ashley from .182 to .046, and Chris Robinson improved from .16 to .03. The formula of the trendline indicates that a catcher who allows a passed ball every five games (.2) at age 22 will allow just .085 per game at 26-28–a below-average mark, but one that is not necessarily unplayable, falling on the good side of .1.

In summary, while it’s easy to look at the passed ball numbers of certain young catchers and wonder how it’s possible that they’ll ever improve enough to come anywhere near capable of receiving pitches at the game’s highest level, there should never be much fear that a catcher will be letting dozens of pitches by in the prime of his career, to say nothing of the passed ball statistic’s woeful inadequacy at capturing receiving or even blocking skill in the first place. Still, a catcher’s passed ball rate at 22 does have some predictive value with regard to passed ball prevention a few years down the line, so 22-year-old catchers who are behind their peers are somewhat likely to stay behind their peers–it’s just that the gap between good rates and bad rates closes dramatically as the players gain experience and eliminate many of the head-scratching plays that come to characterize a facet of the minor league baseball experience.