Zack Wheeler, His Control and RISP

            Much has already been written about the control problems that Zack Wheeler has, it’s been a topic since the Mets traded Carlos Beltran to the Giants for him mid-2011. It became a bigger topic when he reached the majors and finished the season with a 10.7 BB%, which would have been second worst among qualified major league starters in 2013. His 19.5 K% would have fit right in between John Lester and C.C. Sabathia at 45 overall, of 79 qualified starters – not elite like in the minors, but still a little above the league average for starters. Despite his high BB% and apparent average strikeout stuff, he managed an ERA- of 96, which means he was 4% better than the league. Of course all this was done over his first 100 IP in the majors, a small sample size for sure. I wanted to see if anything about his season stood out as a warning for regression or as evidence he could repeat success given he maintains his current K/BB %’s. One thing that stood out was his high LOB% - 77.8, which would have been 17^th best in 2013.

            This is a good point to discuss LOB% some. The formula for LOB% is listed below (per Fangraphs)

 LOB% = (H+BB+HBP-R)/(H+BB+HBP-(1.4*HR))

It represents the percentage of base runners a pitcher strands during the season, duh. Typically pitchers will see their LOB% fluctuate from season to season, but stick around the league average of 70-73%. High strikeout pitchers seem to be capable of maintaining a higher LOB%, as they have less reliance on balls in play. For Wheeler, his LOB% was in the average range during his minor league career (except for the 6 game stint after the Mets acquired him, when he showed elite control and strikeout stuff). Considering he only has 17 starts over ½ a major league season, I don’t think we know enough about how Zack Wheeler will pitch in the major leagues to try and predict whether his LOB% will regress in 2014 or not, though it is certainly a risk. However, I was curious if I could determine how he was able to stay above average, which brings me back to the control topics I initially wanted to discuss.

            Some pitchers talk about having a different mindset when the bases are empty versus when runners are on base and in scoring position. With nobody on base, they are looking to get quick outs and are less afraid of the long ball. Once runners get on and in scoring position, they focus on not making a mistake. Tom Glavine is often mentioned as someone who pitched well with RISP because he would make the hitters hit his pitch – he wasn’t afraid to walk hitters so long as he didn’t make a mistake that could lead to multiple runs. This is evidenced by the fact that for his career, his walk rate more than doubled with RISP, but his PA/HR rate increased and ISO against decreased as well.

Small sample size rules apply, but Wheeler seemed to have taken that approach in 2013. This is noticeable in comparing almost all his stats with the bases empty to his stats with runners on and in scoring position (see tables below). 

Table 1 - Statistical comparison of Wheeler's 2013 with the bases empty vs runners in scoring position.

Wheeler	TBF	BABIP	OBP	ISO	wOBA	K%	BB%	FIP	Pitches	Ball %
Empty	245	.291	.335	.166	.339	16.7	8.2	4.96	972	37.7
On-base	186	.261	.317	.080	.269	23.1	14	3.22	753	40.4
In Scoring	111	.233	.327	.053	.253	26.1	18.9	3.36	482	43
Total	431	.279	.327	.369	.309	19.5	10.7	4.17	1725	38.9

To start, notice that he faced 57% of batter with the bases empty, and 26% with runners in scoring position, and batters reached base against him at about the same rate in both cases, about a .330 OBP. He actually had an acceptable 8.2 BB% and average 62.3 strike % with the bases empty. However, the rest of the chart gives an idea of how he changed his approach as he got in trouble. The more trouble he was in, the more pitches he threw out of the strike zone. This led to a 10% increase in both K% and BB% from bases empty to RISP, and a decline in the quality of contact being made, as evidenced by a huge drop in ISO and BABIP. Altogether, Wheeler became a much tougher pitcher with RISP, improving his wOBA against from .339 to .253 – or from facing 2013 Crisp/Loney to facing 2013 Darwin Barney with über patience. Batters could still reach base against Wheeler with a walk, but could not make good contact.

The improvement in FIP seen during those tougher situations is very much related to how Wheeler did not give up any HR with RISP (see table below).

Table 2 - Continued statistical comparison.

Wheeler	GB/FB	LD%	GB%	FB%	HR/FB%	HR	PA/HR	PA/XBH
Empty	1.43	24.9	44.2	30.9	16.1	9	27.2	13.6
On-Base	1.12	21.2	41.6	37.2	2.4	1	186	26.5
In Scoring	0.83	25.4	33.9	40.7	0	0	-	55.5
Total	1.30	23.5	43.2	33.3	10.2	10	43.1	17.24

This table is interesting because it shows that his LD rate didn’t change very much, and was actually higher than average, but his FB rate increased about 10% at the expense of his GB rate. This could indicate that his BABIP would’ve regressed in time, but the lack of HR’s and XBH’s with RISP indicates a lack of quality contact being made overall.

            There is definitely evidence that Wheeler changed his approach as he got in trouble during the 2013 season. He is still a young pitcher with only 100 IP under his belt, so whether he is this type of pitcher for his career, or can even keep such a pace up, is yet to be determined. I think it’s a mature approach to not always go for the strikeout with the bases empty, as it can save his arm for an extra batter or inning later, but would like to see him walk less with the bases empty. He has excellent stuff, and he can still over power a lot of hitters at the major league level. Overall, I would like to keep an eye on how he approaches and fares this season with RISP, and how that affects his LOB% (Glavine finished his career at 74 LOB%). I think his numbers with bases empty should improve as he gains confidence, and that he can improve overall upon his solid rookie season in 2014.