Barry Zito is having his most successful year as a San Francisco Giant, but one might ask, why?The first number that jumps out when taking a look at his stats this year, is his O-Swing Percentage - the percentage of his pitches out of the zone that yield swings. His career average is 22.1%; this year's percentage? 32.1%. Zito has been effectively getting hitters to chase his pitches. And he knows it: This year, he has thrown a career low 46.2% of pitches in the strike zone; yet his BB/9 is in check: he has a walk rate of 3.35 BB/9, which is actually below his career average. Why? Because he's getting hitters to chase his pitches outside of the zone.
An even closer look at his pitches, and one can see the pitch he has most improved, the fastball. This is a chart of the values of Zito's fastball each year, in terms of runs above average. From 2007-
2009 (Zito's first three years with the Giants), Zito's fastball was used ineffectively, carrying negative value. But in 2010, it has jumped to a 9.3. Let's take yet an even closer look at how Zito is using his fastball.
Here is a chart (vs. RHB) of Zito's 8 shutout innings with 10 strikeouts against the Mets on July 16, 2010. As you can see, he uses the 4-seam fastball (FA) high, above the strike zone to get hitters to chase.
Here is a chart of LHB from that same night. Zito is even more effective at getting left-handed hitters to chase his fastballs. Here they swung at 3 high 4-seam fastballs, 1 outside 4-seamer. That's 4 fastballs out of the strike zone that he got hitters to chase. This skill has improved his pitching efficiency, and nicely sets up his low-and-outside curveball. Zito's stats against left-handed batters are highlighted by this chart: a 9.84 K/9, a 4.78 BB/9, and a .196 opposing average. Basically, he's effectively wild against left-handed hitters. He walks more, but he also strikes out more and gives up fewer hits because of it. This has led to his success.
All charts/data courtesy of Fangraphs
