Quality Pitch % (QP%) and QP%+

There are many metrics to evaluate how good a pitcher is. From tradition metrics like ERA and WHIP to Sabermetrics with FIP and WAR to Statcast era metrics like Whiff% and CSW%, there are so many out there. Recently, there is a trend to look at swing and miss ability of a pitcher as a main metric for how good a pitcher is but really you should look at several. What I think is missing right now is looking at command + stuff in a metric, so what I propose here is quality pitch % (QP%) and QP%+ to evaluate this.

First we need to define what this metrics encompasses. What really is a quality pitch? Well, could be a pitch that is at the edge of the strike zone (shadows) but also a swing a miss pitch. Even if not called a strike for the umpire or contact, hitting the edge of the strike zone is a good pitch. In addition, a pitch could be anywhere and a hitter missing it shows it was a good pitch. Alas, we have a definition! The formula then becomes:

QP% = (# Shadow Pitches + # Swing and Miss Pitches)/(Total Pitches)

We will select the data with this criteria from BaseballSavant, looking at starting pitchers with at least 1000 pitches for the 2024 season and relief pitchers with at least 750 pitches in 2024.

Starting Pitchers

Let’s look at the top starting pitchers in QP%

	Name	Quality Pitches	QP%	QP%+
1	Yamamoto, Yoshinobu	671	53.8%	126
2	Snell, Blake	836	52.7%	123
3	Crochet, Garrett	1198	52.5%	123
4	Gallen, Zac	1212	52.4%	122
5	Perez, Martin	1065	51.7%	121
	Ryan, Joe	1088	51.7%	121
7	Crawford, Kutter	1360	51.6%	120
8	Flaherty, Jack	1262	51.5%	120
	Castillo, Luis	1472	51.5%	120
	Ober, Bailey	1252	51.5%	120
11	Anderson, Tyler	1418	51.4%	120
	Imanaga, Shota	1232	51.4%	120
	Woo, Bryan	752	51.4%	120
	Gibson, Kyle	1341	51.4%	120

We see players that have great stuff like Snell, Yamamoto, Gallen, and Castillo but also interesting names like Crawford, Perez, and Anderson. Crawford (4.19 ERA, 103 ERA+) and Perez (4.36 ERA, 96 ERA+ but better with Padres) don’t jump off the page but Anderson (3.60 ERA, 118 ERA+ and All Star) has turned in an exceptional year.

Relief Pitchers

Let’s look at the top relief pitchers in QP%

	Name	Quality Pitches	QP%	QP%+
1	Nardi, Andrew	509	56.2%	146
2	Hader, Josh	581	54.3%	141
3	Clase, Emmanuel	489	54.3%	141
4	Miller, Mason	498	54.2%	141
5	Lee, Dylan	424	53.5%	139
6	Iglesias, Raisel	450	53.3%	138
7	Erceg, Lucas	467	53.2%	138
8	Yates, Kirby	498	53.0%	138
9	Estrada, Jeremiah	494	52.5%	136
10	Cano, Yennier	481	52.4%	136

We see similar trends to the starting pitchers with Hader, Close, Miller, and Iglesias a few here with fantastic stuff but very surprisingly Nardi (5.07 ERA, 89 ERA+) is at the top.

So what does all this result in? Well, we can evaluate a pitcher’s ‘pitchability’ by using QP% but it doesn’t tell the whole story, just like the other metrics. However, I think we should look at this because if a pitcher locates, they should have more success. You can’t teach command, but you can work on spin rate, break, etc. in the pitching lab.

Data

Baseball Savant