Shelby Miller hard to hit up in the zone

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Shelby Miller's 2.21 ERA is the lowest this season among all rookie qualifiers.(The St. Louis Cardinals host the Chicago Cubs, Monday at 7 ET on ESPN and WatchESPN.)

Ten rookies on the St. Louis Cardinals pitching staff have combined to throw 221.2 innings this season, and are 17-8 with a 3.17 ERA. That’s one reason the Cardinals’ 3.29 team ERA is second this season only to the Atlanta Braves (3.23).

The Cardinals' crop of rookie arms has been led by Shelby Miller, who ranks sixth in the National League with 91 strikeouts. He has struck out 29 percent of batters faced, which is the highest rate in the National League this season.

He has been most successful when he climbs the ladder with the fastball. More than 40 percent of his strikeouts (39 of 91) have come on high fastballs. When Miller throws his fastball up in the zone, opponents are hitting .079 (6-for-76) and have missed on 36 percent of swings (league average is .232). When his fastball is down or in the middle of the strike zone, opponents hit .270 with a miss rate of 15 percent.

Highest 2013 Strikeout Rate

The last time Miller took the mound for the Cardinals, he allowed four earned runs – the first time in 14 career starts that he allowed more than three earned runs.

Wood Channeling His Inner Greg Maddux

Opposing Miller will be Travis Wood, who has a 2.65 ERA and has made a quality start in 12 of 13 appearances this season.

If Wood has a quality start on Monday, he’ll be the first Cubs pitcher since Greg Maddux in 1988 with 13 quality starts within the team’s first 68 games.

What’s fueling his hot start? He’s dominated left-handed hitters. Lefties are hitting .155 against Wood, that’s the fourth lowest opponent batting average this season.

He’s also done a much better job this season of keeping the ball in the ballpark. In 2012, he allowed 25 home runs, and gave up 1.44 home runs per nine innings pitched. This season, he’s allowed six home runs, and 0.64 per nine innings.

Wood has also benefited this season from the lowest opponent batting average on balls in play (BABIP) among all qualifiers at .218 (league average is .295). The low average is not because he's generating weaker contact. According to Inside Edge, which tracks well-hit balls, Wood has allowed hard contact on 16 percent of at-bats, a rate not significantly lower than the 16.5 percent league average.

Wood has recorded 21 outs on what were deemed hard hit fly balls or line drives. That's the fifth-highest total this season. Opponents have hit .524 against Wood when generating a hard hit fly ball or line drive. That sounds like a nice clip, but it's actually the lowest rate among qualifiers and well below the league average of .712. Going forward, Wood shouldn't expect to convert outs that efficiently on hard-hit balls.