This article is part of our DraftKings MLB series.
Pitcher
Luis Castillo, CIN at PIT ($9.500): Both pitchers in this contest are potential selections, but I am going with Castillo in large part due to his extreme groundball rate, as the Pirates have kept the ball on the ground at a 46.7 percent clip. It is also worth noting that Pittsburgh has notched a bottom-5 mark against right-handers this season according to wOBA.
Jack Flaherty, STL at SF ($6,700): There are a number of inherent risks that come with selecting a pitcher making his major league debut, but Flaherty won't have to do very much to return value against the Giants, who hold the lowest wOBA in the league against right-handed pitching. The prospect has tallied a combined 2.18 ERA with 147 strikeouts over 148.2 innings in time split between Double-A Springfield and Triple-A Memphis this season.
Catcher
Chris Iannetta, ARI at COL ($3,500): Iannetta has flown under the radar against lefties this season, as he has tallied a .237 ISO and a .421 wOBA against his opposite hand over 59 at-bats. Kyle Freeland has thrown the ball well, but owns just a 59:47 K/BB ratio against right-handed hitters over 106.2 innings, which has contributed to an xFIP approaching 5.00.
First base
Logan Morrison, TB at CWS ($4,400): Opposition starter Reynaldo Lopez has been knocked around in his only two starts with the big club this season, allowing eight runs and seven walks over 10.1 innings. The 23-year-old will be returning from the disabled list without the benefit of a rehab start, which could make him an easy target for a hitter like Morrison, who has logged a .295 ISO against right-handed pitchers over 332 at-bats.
Second Base
Neil Walker, MIL vs. WAS ($3,500):Tanner Roark has allowed a .473 slugging percentage against left-handed hitters in 2017 while keeping a groundball rate of 49 percent. Walker has tallied a .191 ISO against righties and should be able to get the lift necessary to do damage against Roark, as he has hit the ball in the air at a 42.4 percent clip.
Third Base
Mike Moustakas, KC at MIN ($3,800): It's unfortunate that we don't have more quality lefties to take advantage of Dillon Gee, who has allowed a .541 slugging percentage over 14.1 innings this season. Moustakas should be considered a bargain when he can be owned for less than $4,000 against a righty, as he has registered a .290 ISO and a .370 wOBA through 341 at-bats.
Shortstop
Didi Gregorius, NYY vs. BOS ($3,900):Doug Fister has a knack for keeping the ball on the ground, but that may work against him in the matchup against Gregorius, who has notched a 42.6 percent fly ball rate this season. Fister has allowed a 1.6 HR/9 rate against his opposite hand, while Gregorius has notched a .228 ISO against righties over 312 at-bats.
Outfield
Giancarlo Stanton, MIA vs. PHI ($5,600): Stanton won't come cheap, but there are some unique advantages that come with selecting him against Nick Pivetta, who has allowed a .642 slugging percentage against same-handed hitters over 51.1 innings. The 24-year-old has registered a -12.0 RAA with his fastball this season, which should give Stanton a leg up in his quest to break the 60-home run barrier, as his 28.6 RAA against the heater ranks as the fourth highest mark in the league among qualified hitters.
Khris Davis, OAK at SEA ($4,000):Mike Leake has allowed a 34.7 percent hard contact rate against right-handed hitters this season and has kept the ball on the ground at a 54.5 percent clip. Davis has feasted on right-handed pitching, tallying a .305 ISO, while also sporting a 42.7 percent fly ball rate.
Max Kepler, MIN vs. KC ($4,200): Kepler will bring his 11.0 RAA against the fastball into the matchup with Jason Hammel, whose heater has registered a -3.2 RAA this season. The lefty isn't known for his power but has notched a .234 ISO against opposite-handed pitchers.
