Red Sox Hitters Have Favorable Matchup Against Joe Kelly
With the series tied 1-1, the Boston Red Sox travel to Busch Stadium to face Joe Kelly and the St. Louis Cardinals. Kelly posted a 2.69 ERA over 124 innings during the regular season. In the second half of the season, only three pitchers had a lower ERA than Kelly’s 1.91.
However, the ERA is misleading. Kelly’s strikeout and walk rates were just 14.9 percent, and 8.3 percent, respectively. In the second half, these numbers declined to 12.7 percent, and 9.0 percent. Despite owning a fastball that averaged 96 miles per hour, his swinging strike rate was just 6.3 percent. To compare, Barry Zito and his 83 mile per hour fastball were at 7.2 percent. Overall, Kelly’s numbers suggested that he is an average starting pitcher.
Kelly managed to suppress his ERA by holding opponents to a .158/.238/.233 line with runners in scoring position. This number tends to be more fluky, rather than indication of a skill. Pedro Martinez allowed a .209/.279/.303 line with RISP over the course of his career. It’s foolish to say that Joe Kelly morphs into Pedro Martinez with RISP. Additionally, the difference in the batting line is due more to a reduced batting average on balls in play, rather than improvements in strikeout and walk rate.
In the playoffs, Kelly has been serviceable. Over three starts and 16.1 innings, he has allowed nine runs, with strikeout and walk rates of 18.1 percent and 8.3 percent. His swinging strike rate is up to 10.1 percent.
One thing Kelly does well is get righthanded hitters out. Righties have managed just a .654 OPS against Kelly. Granted, there’s not a whole ton of plate appearances to back that up, but it’s what you would expect from a pitcher with a heavy sinking fastball. His ground ball rate against righties is a solid 54 percent. Strikeout and walk rates are 17.0 percent and 7.4 percent.
Lefties are another story. They possess a .793 OPS against Kelly. His tailing fastball isn’t quite as effective, and the ground ball rate drops to 48 percent. Strikeout and walk rates decline to 13.8 percent and 9.0 percent.
Unfortunately for Kelly, the Red Sox will have several good lefty hitters in their lineup Saturday night. Here are the numbers against righthanded pitchers for the five lefty hitters that should be starting for the Red Sox. It can be dangerous to read too much into platoon splits from one year, but they can tell us something.
Daniel Nava: .292/.390/.443. 129 wRC+. 2013: 146 wRC+.
Jacoby Ellsbury: .302/.353/.460. 115 wRC+. 2013: 133 wRC+.
Jarrod Saltalamacchia: .263/.327/.469. 110 wRC+. 2013: 135 wRC+.
Stephen Drew: .275/.343/.451. 105 wRC+. 2013: 137 wRC+.
I doubt that he’ll replace Shane Victorino (who has abandoned switch hitting after an oblique injury) but Mike Carp hammered righties to the tune of a 144 wRC+ in 2013. You get the picture, these guys can hit righthanded pitching, and Kelly struggles against lefthanded hitters.
Joe Kelly might have a nice ERA, but the Boston Red Sox will be a tough matchup for him. He should come out with guns blazing, firing in his best fastball. If he tires early, so be it. With a loaded bullpen, the Cardinals don’t have to worry about him providing innings for them. His best chance is to take advantage of Boston’s weakness against the heat.