We’re watching history in the making. Josh Tomlin is the best pitcher of our lifetimes at avoiding walks. Since 1900, only Cy Young, Deacon Phillippe, and Babe Adams have lower BB/9 among qualified starters, and all of them retired more than 90 years ago. Here’s the top of the leaderboard (courtesy of FanGraphs):

 
The top seven all time in BB/9 include four great Deadball Era pitchers, two outstanding relievers, and Tomlin. Needless to say, he’s in very good company, even though his results are far inferior to his counterparts on this chart as indicated by ERA, FIP, and WAR.

This season, Tomlin has been even more extreme than usual. Through Sunday’s action, he’s the MLB leader in BB/9 (0.6) and K/BB (9.75). He’s also among the worst pitchers in H/9 and ER. Part of this can be attributed to bad luck on batted balls. His BABIP allowed in 2017 is .335, far higher than his career .280. 

But perhaps there’s a larger problem. Tomlin’s career numbers have been mediocre despite stellar walk rates. Is it possible he’s allowing too much contact? Would it behoove him to walk a few more batters to give up fewer hits?

Tomlin throws five pitches: fourseam fastball, sinker, change, curve, and cutter. Here’s his career results for each pitch with a three-ball count, courtesy of Brooks Baseball:

 
He usually eschews the breaking balls with a three-ball count, as do most pitchers. The results on the fourseamer aren’t too bad. The cutter is another matter entirely. Opposing batters against Tomlin’s cutter with three balls have a slightly better BA and SLG than Ted Williams.

So why does he use the cutter? Perhaps he has been reticent to throw a breaking pitch that might have a greater chance of being ball four. Fourseamers and cutters are easier to throw in the strike zone because they have less movement.

In 2017, his aversion to walks has intensified, but he’s also given up more hits. Here’s his three-ball pitch usage this season:

 
He’s throwing the sinker more often and with mostly satisfactory results. He’s thrown 18 of them and yielded only a pair of singles and a walk. The problem is he’s throwing the sinker in lieu of the fourseamer, not the cutter. In fact, the cutter is getting hit even harder this season while the fastball has been pretty good, though obviously sample sizes are way too small to say conclusively.

So it could possibly all come down to pitch selection. It would be reductionist to say he should just throw the cutter less and the fastball more. If hitters knew he would almost always throw a fastball in a three-ball count, and that it was nearly always a strike, they would knock him out of the league. However, throwing a few more breaking pitches behind in the count might be worth a try. He may end up with a few more walks, but he could also give up fewer hits and runs.

This past Sunday, Tomlin had his best start of the season. He threw a complete game against the Royals allowing only one run on a Jorge Bonifacio home run. He struck out three and gave up only six hits and no walks, of course. He only reached a three-ball count twice, getting Mike Moustakas to pop up to third and Brandon Moss to ground out to second. 

If he had gotten behind in the count to more hitters, would he have pitched as well? Probably not, because no one pitches well behind in the count. The difference between Tomlin and other pitchers is that when he falls behind he is much more likely to give up hard contact than yield a free pass to first.