This is a very rough idea. But If figured that Jeff Niemann had to be doing something well that can be picked up through pitch f/x. And like most of my ideas, the balls and strikes count popped up in my mind as a possible lead. The results were quite shocking to me. The following table is Niemann's run value per 100 pitches, BABIP, and SLGCON for the five counts states with the MLB average for behind in the count included.

Yikes! When hitters put the ball in play when ahead of the count (behind for Niemann), they get considerably less bases and got on base less than the MLB average and the other four count states. Although run values somewhat favor good things more behind the count for a pitcher, that doesn't explain the low balls in play rates.

Here are some general pitch f/x rate stats for Niemann behind in the count compared to the MLB average.

The only major difference I see is more contact by Niemann compared to the average. So why don't you look at that.

I saw it glaring it in my eye. The PU stands for Pop Up around the infield which translates in baseball as "automatic out". This lowers BABIP and SLGCON quite a bit as it gets outs and keeps them in the ballpark.

I have been comparing Niemann to the MLB average. Now let's see where he ranks among pitchers with relatively the same sample size.

When behind the count, Niemann has the 2nd lowest BABIP and SLGCON, and the second highest pop up rate out of 138 MLB pitchers (don't ask me who was 1st, because they were three different pitchers). And for run values, Niemann had the fourth best behind Joel Pineiro, John Lackey, and Jarrod Washburn.

Adding the pitch f/x element into it, we can find the run values by pitch, namely Niemann's highly used fastball. His fastball has the best total run value (large 400 pitch sample size minimum) and the second best per 100 pitches (Washburn there again).

My feeling is that this is one of those "regressors" and it is more than likely Niemann won't be killing it in this category again come spring time. Although my analysis was really limited, just looking at balls in play and run values. A better analysis of Jeff Niemann would be to take this a step further and look at the sequence of his pitches. More to the point, what happens when he throws fastball-fastball-fastball or fastball-breaker-fastball or something along those lines. I just know his fastball would have to be in it quite a bit.

Notes:

Here are is the link to his splits based on the count at Baseball Reference.

TIZ is takes in the zone and IWZ is in the wide zone or pitches tracked in the pitch f/x strike zone (two feet wide between the designated top and bottom of the batter's strike zone. OSWING is a swing outside this pitch f/x strike zone.

Here is the spreadsheet for MLB pitchers when behind in the count (400 pitch minimum).