Reviewing the Rotation, part I: R.A. Dickey

As we approach the one-quarter point in the season, it is obvious that the starting pitching has been a huge weakness for the Blue Jays, collectively ranking 28th in MLB by ERA (5.22) and dead last by both FIP (5.30) and xFIP (4.91). Both process and results are awful. So for each member of the starting rotation, I'm going to look at what's gone wrong, and what we can reasonably expect going forward. First up, R.A. Dickey.

Dickey's first two years in Toronto were disappointing given the expectations coming in, but he had settled in as a serviceable, innings eating, mid-rotation starter. Unfortunately so far, Dickey hasn't come close to even that level of performance:

I've included numbers for comparison from his time with the Mets for reference in discussing longer term trends. So far this year, Dickey's ERA is up by over a run, and his FIP by even more, about 1.3 runs. In terms of batted balls, Dickey's numbers are more or less in line: his BABIP is very low, likely to regress upwards; his ground ball rate is slightly up but basically in line; and he's given up basically an extra home run compared to league average given his fly balls. There will be some regression, likely pushing his ERA and FIP closer together, but the main problem isn't here.

The real culprit has been walks and strikeouts. In his first two years with the Jays, Dickey posted almost exactly league average strikeout and walk rates, at 19% and 8% respectively. In 2015, his strikeout rate has collapsed to 10.5% with no strikeouts in three of his last four starts. At the same time, his walk rate has increased by about 2% as well. While it's only been seven starts, and we should expect a fair amount back the prior expectation (basically, what he did the last couple years), there's also the reality that older pitchers can fall off a performance cliff. Is that the case?

The first and most obvious thing to look at is Dickey's knuckleball velocity. And indeed, with an average of 75.4 MPH, it's definitely at the very low end of where it's been over the last six years:

However, it's been that low before, both to start 2013 and to end 2014. And while lower velocity has coincided with previous struggles, his strikeouts and walks have held up alright during these periods: around 17% K-rate and 8% walk-rate when his velocity dipped in 2013, and 19% and 7% in the second half of last year. This would suggest velocity alone is not the culprit for this year's poor strikeout and walk results.

So what's going on? One thing is that batters are being more selective, taking 55.5% of Dickey's pitches, compared to 53% last year. This is principally because Dickey hasn't been in the zone as much. Across MLB, when batters take pitches, the split is about 2:1 balls to called strikes (36% to 18%). Last year, Dickey was almost right in line at 35% balls to 18% called strikes. But in 2015, Dickey has been much worse, with 38.5% called balls to 17% called strikes. That might not sound significant, but it's a net of about four pitches a game, and consider that the best framers in the game net on average about one strike a game.

A big driver of this is what's happening on the first pitch:

Ball% and Call% are the rates of total pitches called ball and strikes, ahead% adds in fouls and swinging strikes to calculate how often the pitcher gets ahead in the count, and net% is the difference between how often the pitcher is ahead and behind after the first pitch. Across MLB, pitchers get ahead just under 50% of the time, fall behind just under 40%, for a difference of just over 10%.

In his first two years in Toronto, Dickey had favourable mix of called balls and strikes by a net of about 3%, which translated directly into getting ahead of more batters than league average at 12.6%. This year, that's utterly collapsed, to a net of 0 driven directly by the ratio of called balls and strikes. Since this first pitch shift is about double the size of his overall shift, there's reason to think there should be a good dose of regression, which should help. On the other hand, this is part of a longer term trend: Dickey's overall ball/called strike ratio was lower in 2013-14 not only compared to his Cy Young season in 2012 (31%/19%), but also 2010-11 (33%/19%).

The consequence is that in 2015 Dickey has thrown about 28% is his pitches in strong or very strong hitter counts, compared to 23% last year; and 31% in strong or very strong pitcher counts vs. 36% last year. The difference? Batters slugged .561 in those hitter counts. In the pitcher counts? Just .288.

There's one other major change, and that's in Dickey's ability to generate swinging strikes, especially with two out when they matter most:

Dickey's swinging strikes are down significantly, but particularly so with two strikes where he's down 1-in-3. This is the main reason his swinging strikeouts are down from 15% of all batters to 8% this year and is mostly about contact rate, which has climbed about 5% this year overall. Over the past few batters are chasing fewer and fewer balls out of the zone, around 24% compared to 27-30% in 2013-14, and 34% in his Cy Young season, whereas the zone swing rates are quite stable over the same time. This suggests to me a more fundamental element of decline.

The good news is that notwithstanding the above, Dickey's contact rate when in extreme pitcher counts (0-2, 1-2) is extremely out of line on the bad side, even given his overall increase in contact. Unless Dickey has lost the ability to miss bats in a couple of particular counts, he should be able to get a more swinging strikeouts on this alone regressing. My estimate would be this would add about 2-3% to his strikeout rate.

In conclusion, there's two big drivers to see if Dickey can correct and turn around his season: getting called strikes, particularly on the first pitch; and missing more bats particularly with two strikes. Things should definitely improve somewhat regardless purely on regression, but there's also indications that more fundamental decline may be driving the poor results. In which case, expecting even 2013-14 Dickey is overly optimistic.