Tim Lincecum has been pitching at a useful level, but not like his Cy Young peak level of talent for a few seasons now. On Monday night, he decided to go old school and strike out 11 batters. While it may seem like Lincecum is putting it all together again, it's worth pointing out that he was facing the swing-and-miss Braves. Here, I am going to look at how the opposing team can improve a league average starting pitcher to have Felix Hernandez type number, or conversely, bring a pitcher down to the Henderson Alvarez's of the world.
Going against the Braves on Monday, Lincecum had a strikeout percentage (K%) of 21.3%. The Braves had a K% of 23.8%. Averaging the numbers, it seems like the Braves should strike out around 22.5% of the time. This is the wrong approach. The league average K% is 20.5%. Lincecum is striking out batters at an above average pace. Assuming the Braves have seen average league pitching so far, the Braves should strike out even more than 23.8% of the time when they face an above average strikeout pitcher like Lincecum.
I did a little math magic to get the projected K% knowing a pitcher and the team he face. I used odds ratio for determine the projected K%. The math behind it is outlined here in two articles by Steve Staude at FanGraphs. While he used pitcher-hitter matchups, the theory and formulas still apply to the team level. The following is the expected K% for a pitcher knowing his K% and the hitting teams K%
Note: The red numbers show the point where a pitcher has at least a league average strikeout rate.
The hitting team K% range is for the current range this season with the Cubs having the highest K% at 24.3% and the lowest being the Royals at 15.5%. A league average pitcher could see a 10% point swing in his strikeout rate depending on the team he is facing. A 10% swing is huge for a pitcher. A few pitchers with a 15% K% are Josh Collmenter, Henderson Alvarez and Jason Vargas. Those around 25% are Felix Hernandez, C.J. Wilson and Yordano Ventura. An owner can have the likes of Travis Wood (20.5% K%) produce at significantly different levels from start to start.
The big key here is the further both the pitcher and team are away from the league average K%, the more the effect will become. A 25% K% team should expect to strike out over 30% of the time against a 25% K% pitcher. If a person is looking for good matchup, the key to look for is the combination of above average K% for both the pitcher and opposing team.
Looking back at Lincecum, he came into the game with a 21.3% K% and the Braves had 23.8% K%. Lincecum should be expected to strike out ~25% of the Braves. Lincecum went above and beyond and struck out 39%. The resulting game K% will be more or less almost every time, but the odds will even out over the season.
This is not the first time he has faced the Braves. In the first matchup, he struck out only four batters for a 14.8% K%. Adding the two games together, he has a 27% K% against the Braves which is pretty close to the projected 25%.
To help find which teams are more likely to strike out, here is each team's current K%. Additionally, I have included how the team has done against left and right-handed pitchers to see if any hitting team is affect by a certain handedness of pitcher.
The teams to really be looking at targeting with your starters are the Cubs, Braves, Astros, Marlins, White Sox and Twins. Each of these teams should at least give your average starter a 2.5% point boost in K%.
On the other end of the spectrum are the Indians, Rays, A's, Rockies, Tigers and Royals. These teams with cause an average pitcher's K% to drop 2.5% points.
The NL East would be a nice division to target pitching in with both the Braves and Marlins being among the league leaders in striking out.
The AL Central is the Dr. Jekyll and Mr. Hyde division with the White Sox and Twins being on the high K% end of the spectrum and the other three team rarely striking out.
Looking at the differences between right and left-handed pitchers, I would concentrate on the extremes this early in the season. The Marlins and Angels are struggling more against right-handed pitchers while left-handers own the Dodgers.
Fantasy owners sometimes have to choose between seemingly close matchups for pitchers. A great way to break the close call is to look at the potential for a few extra strikeouts gained by knowing the starter's opponent. An average starting pitcher can see a 10% point swing in K% depending on the team he faces. With that much of a swing, the opposing team can change his production from a replacement level pitcher to a possible Cy Young contender.