This article is part of our Regan's Rumblings series.
To me, swinging strike rate has always been a powerful tool in evaluating starting pitching performance. It's a simple calculation (swings and misses generated divided by total pitches), as it measures both the ability to throw strikes (control) aa well as dominance (causing a hitter to swing and miss). We routinely see the game's best starting pitchers faring well with this metric. For example, in 2018, the NL Cy Young winner (Max Scherzer) led all qualified starters with a 16.2 percent mark, while the AL winner, Blake Snell, finished with a 15.1 percent mark, good for fourth in all of baseball. Sometimes we'll get marginal (or even poor) starters faring well in this category, but for other reasons (poor command or control usually), their overall performance is far from elite. Nick Pivetta (12 percent SwStr% in 2018) was a good example last year, while this season, German Marquez (4.97 ERA) ranks 17th with an excellent 12.9 SwStr%.
This week, I'll be covering the 10 starting pitchers (who qualify for the ERA title) who have showing the biggest first half / second half leap in their SwStr%. Other factors certainly come into play, but an increase in dominances as measured by this metric is certainly a good sign.