Randal Grichuk poised to breakout

How about that walk-off from Randal Grichuk last night? Randal has had it a bit rough to start the season, but he's starting to heat up. Last night's homer brought his overall batting line up to a 97 wRC+, almost back to average. He had a pretty amazing season last year, in all likelihood the best season he'll have by a rate basis, with a 137 wRC+ and 3.1 fWAR in 350 PA, or about 5.3 WAR/600 PA. The worry though was that that line was propped up by a high .365 BABIP that would probably regress a lot going forward. His .272 ISO would probably regress too, as when adjusted by contact, Grichuk had the 3rd largest ISO in the league last year, behind just Chris Davis and Bryce Harper.

Grichuk struck out over 30% of the time last year, and walked just 6.3% of the year, so the fear was that with any slippage in his superb contact quality, his profile would fall apart. Grichuk did not get enough plate appearances last year to be a qualified hitter last year, but if he did, he would have recorded the highest qualified K-BB% of the last three years. Batting Average on Balls In Play (BABIP) varies a lot year to year, so while Randal looked like a God when it was going his way, he could look pretty awful when it wasn't .

You know though, Baseball be crazy. Randal has had a bad run of BABIP luck, running at .266 including last night's game, over 100 points lower than 2015's BABIP. His ISO, while still a healthy .191, is 81 points lower than his 2015 ISO. Had Grichuk's K and BB numbers been the same as last year, his line would have been ugly enough that there probably would have been an outcry among large portions of the fanbase to demote him when Tommy Pham returned. But some rather large improvements in Grichuk's K and BB game has kept him afloat.

These numbers look sustainable for two reasons: he's improved his contact rate, despite a decline in contact rate league wide, and he's improved his O-Swing%, even more so than the league rate has improved.  I wanted to see how Randal's contact differential fared league-wide, that is, where you could rank his improvement. So using some programming skills, I wrote a script comparing each player with at least 350 PA in 2015 (Grichuk's total) and a qualified amount of PA in 2016, and took the difference between their Contact% in 2016 and 2015. Randal came in 20th out of 147, and teammate Matt Carpenter came in 10th. Here's the stretch from Marp to Grichuk, using stats updated yesterday, before yesterday's game's were added in:

As you probably assumed, a rise in contact rate will generally coincide with a drop in K%, and that's also been the case with Matt and Randal. Grichuk had a rather large jump, but he also has lowered his O-Swing% as well, which would also help cut down on K's, as well as raise his walks. Going by the difference between 2016 and 2015's O-Swing%, Grichuk was well above average at 43rd. He came in front of Carpenter at 59th:

I also added Zone Swing differential to add additional context about how the player had changed in 2016. Randal's Z-Swing% went down, but not nearly as much as his O-Swing%. The BB% gain may be a little higher than other players with similar O-Swing changes, but only by a little bit.

So we have underlying reasons for why Grichuk should be doing better in the plate discipline department. And we also see it in action, with some massive decreases in his K-BB% rate. Take the decreases in K%, and the increases in BB%, and Randal has been one of the most improved players in the game in terms of strike outs and walks. Next, working with the same player seasons (350 PA in 2015 and qualified so far in 2016) I took each player's K-BB% in 2015 and 2016, and found the most improved players in terms of K-BB% this year:

Randal comes in fourth here in terms of biggest improvements, quite the nugget of truth buried beneath Grichuk's lower BABIP and ISO numbers. Randal really needed this more than anyone, with his extremely high strike outs and very low walk totals last year. In my last piece I wrote on Grichuk, I pointed out the extremes in his profile and worried about how bad he could be with less success on balls in play. League average K-BB% is 12.7%, and before yesterday's game Grichuk sits at 13.5%. In one year Grichuk has gone from one of the most extreme profiles to basically normal, which is pretty extraordinary if you ask me.

One last thing I wanted to look at was the different tiers of players in terms of K-BB%, as well as the average wRC+ for each tier. Here is a graph of each player season with at least 350 PA from 2012 to 2015, separated into groups. The first group is those with K-BB% under zero, that is, they have more walks than strikeouts. Then the second group is those with a K-BB% of more than zero but less than three, with group three with a K-BB% of less than three but more than six. It goes like that all the way to the eleventh group, which is reserved for those with more than  a 27% K-BB%. Here are those eleven groups, presented as a line graph identifying how many players are in each group, as well as their average wRC+:

The chart options are giving me some issues that aren't allowing me to label the horizontal axis, but at the left end starts group 1, those with a negative K-BB%, and at the very right end is the last group with more then a 27% K-BB%. The Red line indicates the average wRC+ of each group (not weighted for plate appearances for simplicity) and the blue line indicates the amount of players in each group. Notice how most players trend towards average, and how the Red line drops as K-BB% rises. There is certainly survivor bias in these results, as a player with a 24% K-BB% is going to have to be much better in BABIP and ISO to make up for it.

Grichuk has went from the tenth group (more than 24% but less than 27%) to the sixth group (12% to 15%). That's going from a group average wRC+ of 93 to a 101. To get a better idea of the survivor affects in play, I averaged the BB%, K%, ISO, and BABIP numbers from both the tenth group that 2015 Randal is a part of, as well as the sixth group that 2016 Randal is part of:

Not only was Randal's old peer group 8 points of wRC+ worse than his new group, they needed a 24 point boost in ISO and a 15 point BABIP increase just to get it that close. This chart pretty clearly illustrates the value gained in Grichuk's new profile. And for anyone worried that Grichuk's new approach is costing him contact quality, the advanced stats certainly aren't seeing it:

He's lost a little bit of fly ball distance, but he's actually (very marginally) increased his average exit velocity and his Hard Hit%. At this stage in the year, these differences are not big enough to make anything out of: He's essentially been the same hitter in terms of contact quality. His Line Drive% is down, but while past LD% correlates well with past BABIP, it doesn't correlate well with future LD% or future BABIP. His FB% is right around the same mark. I wondered if I might find that Grichuk's new approach was costing him in terms of contact quality, but I can't find any trace of that in the stats.

With this analysis, I'm very excited to see how Grichuk's 2016 closes up. Will his BB and K numbers stay in this new altitude? If so, he only needs a modest regression in his BABIP and ISO in order to put up a strong season going forward. He'll probably never see the highs of a .365 BABIP again, but his current BABIP is much lower than what should be expected. With the stats showing the Randal is hitting the ball as hard as he did last year, it's only a matter of time until he breaks out.