Roy Halladay, one of four pitchers with three wins, toes the mound Tuesday in an attempt to become the first to four wins if he conquers the Rangers, who are slugging a major league best .535. We could also witness a pitchers' duel in San Francisco, as Jake Peavy and the Padres face the Giants' Matt Cain in a intradivision tilt.
If Mother Nature has her way, however, those could be two of the only contests not subjected to weather delays or postponement. Many games on the East Coast will be threatened with downpour, so keep that in mind as you set your starters for the day.
Starting pitcher rankings for Tuesday, April 21 (* all stats listed are from 2008)
Rk.: The author's ranking of that pitcher for that day only. T: pitcher throws left-handed or right-handed. Record: pitcher's win-loss record. ERA: pitcher's earned run average. WHIP: pitcher's average number of walks plus hits surrendered per inning. K/9: pitcher's average number of strikeouts per nine innings. OPSA: pitcher's on-base plus slugging percentage surrendered to opponents. OPS: pitcher's opponent's composite team on-base plus slugging percentage. CT%: pitcher's opponent's success rate putting the ball in play (versus striking out).
Selected notes: In five career starts against the Royals, Aaron Laffey has a 2.73 ERA and 1.18 WHIP in 29 2/3 innings. Alex Gordon just hit the disabled list and the Royals are also missing their best lefty masher in Jose Guillen, while Laffey's a good bet to receive run support, since the Indians -- who boast the second-best OPS in the majors -- should beat up on Sidney Ponson. He's a good spot-start option who is available in nearly every league. Rich Harden's 18 strikeouts in nine innings have convinced me that his high ERA (5.00) is nothing to worry about, and he could dominate versus the Reds, who are hitting .210 as a team, last in the majors, and may be without one of their best players in Jay Bruce. Oliver Perez only allowed one run in six innings versus the Padres in his most recent start, but it's tough to predict his blowups. The Cards are hitting a robust .288 BA/.372 OBP/.477 SLG to begin the season, and Perez has allowed twice as many fly balls as ground balls in his two starts, so steer clear. This will be Franklin Morales' first start since being sent down to Triple-A after his outing on April 8, and he's facing the Diamondbacks on the road again. Fortunately, the D-backs haven't found their bats in the meantime, as their .280 on-base percentage ranks last in the majors. Morales went five scoreless innings in his Triple-A start and has rare strikeout potential when he's on. In three starts against the Tigers, Jered Weaver has been bombed, with an 8.78 ERA in 13 1/3 innings. The likes of Placido Polanco, Carlos Guillen, Curtis Granderson and Magglio Ordonez are all hitting .500 or better against him, making Weaver a tough play. The Angels' lineup looks a lot less imposing with Vladimir Guerrero on the sideline; they have used Bobby Abreu, Maicer Izturis and Robb Quinlan as No. 3 hitters in recent games. Armando Galarraga allowed only one run versus two tougher offenses in the White Sox and Rangers, so he seems like a no-brainer start against an offense lacking any power. Andy Sonnanstine has a 2.66 ERA in his past three starts against the Mariners, and if anything, their lineup has only gotten worse. He's a strong bet for his first quality start of the season.
• Aubrey Huff, 1B/3B, Orioles: In 22 at-bats versus Jose Contreras, Huff has seven hits -- including a home run -- and six walks. That's not too surprising, considering Contreras has allowed lefties to slug .458 and get on base at a .361 clip the past three seasons.
• Mike Cameron, OF, Brewers: It's only four at-bats, but both of Cameron's hits versus Joe Blanton are homers.
• Jack Cust, OF, Athletics: Although CC Sabathia has struck him out seven times in 13 at-bats, he's also hit two doubles and a home run against the southpaw, along with two walks.
• Hank Blalock, 3B, Rangers: The Ranger with the most success versus Roy Halladay, Blalock is 11-for-33 with two home runs and a .576 slugging percentage.
• Carlos Delgado, 1B, Mets: Is 4-for-7 with two doubles and a home run versus Todd Wellemeyer.
• Mark Reynolds, 3B, Diamondbacks: Struggles against Rockies lefty Franklin Morales, with just one hit and three strikeouts in seven at-bats.
• Adrian Beltre, 3B, Mariners: Has four hits -- including two homers -- in nine at-bats versus Andy Sonnanstine.
• Orlando Cabrera, SS, Athletics: Is hitting .154 (4-for-26) against Sabathia, including five strikeouts.
• Delmon Young, OF, Twins: Young has just three hits in 18 at-bats versus Tim Wakefield, with five strikeouts to one walk.
• Rick Ankiel, OF, Cardinals: Ankiel isn't likely to turn around his rough start when he faces Oliver Perez, who holds left-handed batters to a .195 batting average and strikes them out more than one-third of the time.
• Carl Crawford, OF, Rays: Is 6-for-24 (.250) versus Jarrod Washburn, with only one extra base-hit. Despite three walks and five singles, he has yet to attempt a steal off of Washburn.
• Chase Utley, 2B, Phillies: Is hitless in eight at-bats versus Peavy, with two strikeouts and one walk.
• Kevin Kouzmanoff, 3B, Padres: Has never landed more than a single against Matt Cain, two in 20 at-bats in fact. Cain has also struck him out five times.
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• Cody Ross, OF, Marlins: Nearly half of Ross' hits have gone for extra bases, so despite his .256 average, he has three home runs, 11 RBIs and eight runs in 12 games, including nine hits in his past five games.
• Lyle Overbay, 1B, Blue Jays: Has seven hits in his past four games, including two home runs, two walks, and a double.
• Nick Johnson, 1B, Nationals: Johnson was just moved up to the second spot in the lineup and is hitting .385 with seven runs in 10 games. An on-base machine, the gaudy run totals should stay consistent as long as he stays healthy, and he hits both lefties and righties equally well.
Injury list: Out
• Roger Bernadina, OF, Nationals (15-day DL, ankle; out until July)
• Alex Gordon, 3B, Royals (15-day DL, hip; out at least two months)
• Cristian Guzman, SS, Nationals (15-day DL, hamstring)
• Vladimir Guerrero, OF, Angels (15-day DL, torn pectoral; out for at least a month)
• Kenji Johjima, C, Mariners (15-day DL, hamstring)
• Melvin Mora, 3B, Orioles (15-day DL, hamstring)
• Xavier Nady, OF, Yankees (15-day DL, elbow)
Injury list: Day-to-day
• Garret Anderson, OF, Braves (quadriceps)
• Ronnie Belliard, 2B, Nationals (back; available to pinch-hit)
• Milton Bradley, OF, Cubs (groin)
• Russell Branyan, 1B/3B, Mariners (back; probable)
• Jay Bruce, OF, Reds (hand)
• Stephen Drew, SS, Diamondbacks (hamstring)
• Nomar Garciaparra, SS, Athletics (calf)
• Adam Jones, OF, Orioles (hamstring)
• Jeff Keppinger, SS, Astros (back)
• Evan Longoria, 3B, Rays (foot; probable)
• B.J. Upton, OF, Rays (quadriceps)
• Overall, up to eight games could feel the impact of Mother Nature. Storms are expected to strike the East Coast, and six games could be affected: in Washington, Baltimore, Pittsburgh, Philadelphia and New York. All have at least a 60 percent chance of rain, with New York and Philadelphia a near certainty (90 percent), and Boston isn't out of the woods, either, with a 30 percent chance that grows to 80 percent after 10 p.m.
• The Royals-Indians and Reds-Cubs also have a strong possibility of showers, and it's expected to be windy in both stadiums regardless. Cleveland has the better possibility of skies clearing, as the rain should let up later on, while light rain is forecasted for Chicago all night long.
• As far as weatherproof games are concerned, Rangers-Blue Jays, Dodgers-Astros, Rockies-Diamondbacks and Rays-Mariners all benefit from a dome.
Adam Madison is a fantasy baseball analyst for ESPN.com.