The Mets have scored more runs per game since the change, but what, if anything, has changed about their approach?
Things have gone very well for the Mets lately, and as has been the case for most of the season, there’s been plenty of talk about the team’s approach at the plate. Ever since the Mets dismissed hitting coach Dave Hudgens on May 26 and replaced him with Lamar Johnson, there has understandably been an inclination to compare the team’s performance under the two hitting coaches.
Since May 27, the Mets have played to a 22-22 record. They started play on May 27 with a 23-28 record, dipped eleven games below .500, and got back to five games under with their excellent 8-2 home stand entering the All-Star break. They have been a more productive team at the plate over that stretch.
In 50 games with Hudgens, the team scored 3.90 runs per game, and in 45 games with Johnson, they have averaged 4.18. That, combined with the team’s run prevention over that span, has turned the Mets’ run differential from -13 on May 27 to +19 today. But has their approach to hitting changed?
Anecdotally, Mets players seem to suggest that it has not. Johnson is said to have advised "putting the ball in play and living with the consequences," per a report from Tim Rohan in the Times, but there haven’t been reports of a drastic change in philosophy from Hudgens to Johnson.
On the surface, the Mets have swung the bat slightly more often since Johnson took over than they had beforehand. In June and July, per Fangraphs, they Mets have swung at a higher rate of pitches outside the strike zone (O-Swing%) and in the strike zone (Z-Swing%) and have, therefore, swung at a pitches at a higher rate in total (Swing%).
| Mar/April | May | June | July | 2014 MLB Avg. | |
|---|---|---|---|---|---|
| O-Swing% | 25.4% | 28.0% | 28.3% | 31.1% | 27.7% |
| Z-Swing% | 63.0% | 63.0% | 65.9% | 68.3% | 64.5% |
| Swing% | 43.7% | 43.6% | 45.3% | 48.1% | 44.6% |
Given those numbers, it might be instructive to take a look at the Mets’ swing rates by count to see in what situations things have changed. Thanks to the excellent PitchF/X search tool available at baseballsavant.com, it’s possible to drill down and compare the team’s swing rates by date range. For our purposes, the Hudgens numbers below range from Opening Day through May 26, and the Johnson numbers range from May 27 through July 12.
| Count | Hudgens (Swing%) | Johnson (Swing%) | Change |
|---|---|---|---|
| 0-0 | 25.24% | 25.98% | 0.74 |
| 0-1 | 46.65% | 48.61% | 1.96 |
| 0-2 | 46.82% | 51.16% | 4.34 |
| 1-0 | 42.19% | 42.24% | 0.05 |
| 1-1 | 49.93% | 48.94% | -0.99 |
| 1-2 | 55.47% | 55.92% | 0.45 |
| 2-0 | 38.52% | 37.65% | -0.87 |
| 2-1 | 54.99% | 57.89% | 2.90 |
| 2-2 | 62.22% | 60.65% | -1.57 |
| 3-0 | 4.40% | 10.78% | 6.38 |
| 3-1 | 51.30% | 55.42% | 4.12 |
| 3-2 | 71.93% | 73.35% | 1.42 |
First, there’s been very little change on the team’s swing rate at first pitches. At a change of less than one percentage point, the Mets have swung at one extra first pitch per two or three games they have played. The most significant differences have come in the more extreme counts: behind 0-2, ahead 3-0—a count that often involves a manager giving a red or green light to the hitter—and ahead 3-1. They're swinging very slightly less often in 1-1, 2-0, and 2-2 counts.
So overall, the Mets have swung the bat a bit more since the end of May. They have certainly hit the ball harder and scored more runs in the process. Based on the swing rates, what the players have been saying seems to hold up: The approach has perhaps been tweaked, but is has not drastically changed.