Zack Greinke has been the most valuable National League pitcher this season, tallying 3 WAR over 13 starts. Not too far behind him is a pair of Washington Nationals starters who have each made one fewer start: Gio Gonzalez ranks second with 2.7 WAR and Stephen Strasburg comes in third with 2.6 WAR. At this point in the season the 0.3 wins separating Greinke and Gonzalez isn’t significant, nor is the more minute differential between Strasburg and his southpaw teammate.
But the fact that Gonzalez is even in the same discussion as a former Cy Young Award winner and a phenom living up to the hype bears notice. Entering the season, the 26-year old Gonzalez was considered a good pitcher, one who could easily miss bats but who struggled with control and was prone to racking up walks. He wasn’t projected to pitch at an all-star or award-worthy level, but the Nationals saw something they loved and offered, at signing, the largest-ever contract for a first-time arbitration-eligible pitcher.
His five-year, $42 million deal, which includes a $12 million club option in 2017 and a $12 million player option in 2018, stood to buy out the most effective years of what we typically consider a #2 or #3 starter. The deal offered some savings at the end if Gonzalez turned into an ace, but would still prove worthwhile if he sustained the 3-3.5 WAR performance he established over 2010-11.
If Gonzalez can sustain his current level of performance, or some semblance of it, the Nationals are going to have a legitimate second ace in the rotation and a potential #1 starter signed to a fairly modest deal throughout his prime.
Can Gonzalez keep rolling through the National League at this pace? While there are a couple of reasons to think some of his numbers will regress to the mean, there is also ample evidence to suggest he has made long-lasting improvements and isn’t simply a posterchild for switching to the easier league.
Switching leagues is one of the trickier subjects these days, especially with fantasy baseball becoming so prevalent, where the effects of the league-switch can make a pitcher look better or worse even though the scoring environment dictates the same value. The American League is more offensive-minded with the designated hitter in play, so pitchers switching to the National League tend to see their numbers improve. It doesn’t mean their actual value as a pitcher improved, but their numbers look better when compared to their statistical pasts.
Gonzalez, however, has improved beyond the typical league-switch effects.
From 2000-10, among pitchers who switched leagues from one year to the next, while throwing 100+ innings in both seasons, those switching to the senior circuit improved their strikeout rate by 0.6 per nine innings. The collective walk rate didn’t move much, improving by approximately 0.1 walk per nine innings. Gonzalez has improved his walk rate by over 0.3 per nine, while his strikeout rate has ballooned upwards by almost 2.25 per nine. He isn’t going to continue suppressing home runs at this rate for the entire season — current HR/FB of 1.9% — but his increased strikeout prowess goes beyond getting to face Joe Blanton instead of David Ortiz.
How is he doing it? For starters, he is throwing over a half-mile per hour faster on his four-seam fastball and is throwing it more frequently. He has an excellent curveball but has become more selective with it in order to utilize his changeup more often. While the season is still relatively young, the change in approach has made each of his offerings more effective per 100 pitches than in any of his four previous seasons. His two- and four-seamer, as well as his changeup, are all being thrown with more horizontal and vertical movement than ever before. Put everything together and Gonzalez is attacking hitters differently with better stuff than he has shown in his young and impressive career.
Naturally, his plate discipline marks are all trending in the right direction. Batters are swinging more but making far less contact, and the reduced contact primarily stems from pitches thrown in the zone, where better contact is yielded. His groundball rate has even improved to 49 percent, making him practically the ideal starter. Consider that there are 23 NL pitchers with a 49%+ groundball rate, and Gonzalez has the highest strikeout rate. Only Greinke matches his diverse stat-line in this regard.
These improvements aren’t enough to guarantee his BABIP remains a relatively microscopic .244, or that he continues to serve up homers at a rate of one per 293 batters faced, but Gonzalez is doing things differently this season and seems to be becoming a much better pitcher than many initially thought possible. Switching to the easier league can bring with it a performance boost, but throwing faster, with more movement, and a different approach that keeps batters off-balance is far more significant to his ability to continue pitching at this high of a level. Stephen Strasburg is still the pitching face of the Nationals franchise, but Gonzalez is a major reason the team currently sits four games up on the NL East, playing 14 games above .500.