Since Aug. 14, Jake Arrieta ranks first in the majors with an 0.74 ERA. That’s not a surprise.
In that same time, Clayton Kershaw ranks third with a 1.75 ERA. That’s not a surprise.
Between them sits Toronto Blue Jays lefty J.A. Happ with a 1.68 ERA. That is a surprise.
Happ is the first Blue Jays starter to begin a season 5-0 since Roger Clemens started 11-0 in 1997. He came within one out of his fifth career complete game and first shutout since 2010 in beating the Giants on Tuesday. He entered the day 0-4 with a 6.75 ERA against the Giants, but this is a new Happ.
What is behind the turnaround?
Happ went 4-7 with a 4.78 ERA in his first 22 appearances (21 starts) last season, which encompassed his first 20 starts with the Mariners and his first start with the Pirates (where the turnaround began). The chart on the right shows the difference between when it went bad for him last season and how he has been since the going’s been good.
Past studies into Happ’s improvement have cited an adjustment in Happ’s delivery and the work Pirates pitching coach Ray Searage did on his fastball. Indeed, Happ's strikeout rate is up, and his walk rate and home run rate are down by a good amount.
But one simple explanation for Happ’s better work is that the defense behind him has been better. Although his ground ball, fly ball, line-drive and hard-hit rates were similar in both timeframes, his defense converted only 64 percent of batted balls into outs through the first 22 games, compared to 72 percent by the Pirates and Blue Jays in the past 17 starts. On Tuesday, the Blue Jays turned 18 of 24 batted balls against Happ into outs.
The one fear factor for Happ is that he has allowed very few home runs (7), given the number of fly balls (94) he has allowed, and that could normalize over time, especially given that he pitches in one of the most homer-friendly parks in the majors, Rogers Centre. His xFIP, which attempts to project ERA given strikeouts, walks and fly balls allowed, was 4.44 entering Monday.
For the short term, Happ's next start comes against the Rays at home. He has allowed three home runs (and five runs) in 12 2/3 innings against the team already this season.