An interesting thing about his plate discipline numbers: his swing percentage so far is the highest of his career--but the difference is mostly in his Z-swing component. His O-Swing% has been quite consistent over the years, ranging from a low of 24.4 in 2009 to a high of 26.9 in 2007. This year it's 26.7. These figures have generally been quite near league average (because the league O-Swing has gone up several ticks the last couple of years--perhaps due to PitchFX recalibration?--he's actually better than average this year).
On the Z-Swing% side, Ellsbury was slightly over league average in his 2007 stint, but has been well below it since: 58.8 in '08 and 57.6 in '09 where league averages were 65.4 and 66.0. This year he's right at league average (64.4/64.7). Interestingly, his Z-Contact% so far is a career worst (still pretty decent at 90.6%, but he's usually in the 95% range).
I think the story of this year is that Ellsbury has made a quantum leap in pitch recognition and/or confidence in same. He's seeing the pitches he can drive and pulling the trigger on them more consistently than ever before. Occasionally this leaves him more vulnerable to being fooled (hence the lower Z-Contact and higher K rate), but it allows him to make hard contact far more often (his LD% of 25.2 is way above career norms, as is the .166 ISO). This is a very good tradeoff. A higher BB rate would the cherry on the sundae, but it can wait.
A terrific analysis that I believe needs only one sentence changed (the one in bold).
First, it's not a quantum leap; it's the evolution and maturation
of the major adaptation he made in 2009 at the start of June, when he hit .302 / .365 / .439 the rest of the way. That's why many of this saw this coming (someone has a sig where I quote the argument for his becoming a superstar.)
And it is not pitch recognition, which has always been terrific (making him an excellent two-strike hitter), it's pitch anticipation
, looking for specific pitches much more often, rather that defensively reacting to whatever is thrown.
He used to have great numbers when behind in the count and relatively weak numbers when ahead -- a sure indication of defensive hitting and failure to take advantage of hitter's counts.
These numbers are all sOPS +, which is OPS+ relative to league in same split:
(I didn't even know this year's splits until I looked them up.)
After being ahead 2-0, after being behind 0-2:
2008: 69, 121
2009: 71, 226
2011: 213, 170
Ahead, even, behind in count
2008: 90, 97, 123
2009: 86, 91, 170
2011: 134, 171, 104
And he used to have tremendous splits where he had great numbers only in situations where you might expect him to look for his pitch and drive the ball versus just trying to get on base -- his numbers with the Sox ahead, 2 outs, weak hitter up next were astronomical, while his numbers with the score tied or Sox trailing, 0 outs, good hitter up next were terrible.
0 outs, 1 out, 2 outs:
2008: 78, 106, 111
2009: 85, 108, 136
2011: 123, 184, 120
Sox ahead, tied, behind
2008: 102, 91, 89
2009: 120, 93, 96
2011: 111, 164, 150
B-ref doesn't break down splits by batter following, but as of June 2009 they were startling. A big reason why he used to hit immensely better 8 and 9 rather than 1 is that he didn't have Pedroia following him, so he tried to drive the ball more rather than just get on base.
Now, you might point out that the 2009 numbers show no signs of an adaptation. But if we split them up, first two months versus last four, I'm fairly certain they would. His 2008 tendencies had become that much more pronounced in the first two months of 2009, which is why his numbers were way down. At that point I first discovered this phenomenon (tipped off by pitch/fx data that showed him leading the club at swinging at pitches in the middle of the zone but last in SA when he did, a huge red flag for defensive hitting) and posted about it here. At around that time they happened to drop him in the order, and he started making the adjustments he needed to make -- he started looking for pitches to drive regardless of situation, and started looking for pitches to drive when ahead in the count. Hence his 2011 splits are as predicted back then. (And, yes, the Sox definitely were aware of these tendencies.)