Carlos GonzalezandTroy Tulowitzki
After combining for five homers in a 12--4 win over the Reds on June 5, the two sluggers have both hovered near the magic 1.000 OPS mark and they sit 1--2 in the league in slugging. Those numbers are not a Coors Field mirage—Gonzalez has a slash line of .348/.414/.696 on the road and Tulowitzki is hitting .302/.361/.613 away from Coors. The lefthanded-hitting Gonzalez has arrested a steady decline against southpaws and is hitting .322/.371/.563 against them this year. The most important number? Just eight games missed between them this season. The pair have never both played in 130 games in the same year.
Dustin PedroiaandDavid Ortiz
They're the longest-running set of teammates in this group, but Pedroia and Ortiz rarely hit 3--4 before this season; the signing of Shane Victorino last winter pushed Pedroia, a longtime number 2 hitter, down one spot. Pedroia is having the best season of his career despite hitting just four homers, with career highs so far in average (.333) and OBP (.416). Ortiz, who missed the first three weeks of the season with right heel soreness, has picked up where he left off last year with 13 homers and a 1.031 OPS. The Red Sox are 27--17 when these two hit 3--4, 12--8 in all other games.
Matt HollidayandAllen Craig
The one matched set in this group features two righthanded batters who handle righthanded pitching very well. Holliday has a small reverse platoon split for his career (.922 OPS vs. RHP; .902 vs. LHP) and Craig, who crushes lefties (.311/.344/.580), is a career .299 hitter against righties. While their 2013 numbers aren't quite as impressive as their '12 ones were, these two have been the lineup core for the best team in baseball to date, one that is second in the NL in runs scored. Holliday and Craig have combined for an amazing .378 batting average with runners in scoring position.
Pablo SandovalandBuster Posey
For the moment, anyway. After more than a year of batting the two hitters 3--4, Bruce Bochy has experimented in recent days with Posey in the third spot and Sandoval in the five hole. The Panda, who hit three homers in Game 1 of the 2012 World Series, is batting .289 this year but has just 12 walks and 15 extra-base hits. Meanwhile, Posey is repeating his MVP work of '12: .302/.381/.502. This combination slugged the Giants to a world championship just last October, and they're the youngest elite 3--4 combo in the majors—each is just 26 years old. Look for a big second half from the duo.
PHOTO BY DOUG PENSINGER/GETTY IMAGES (ROCKIES)
BARRY CHIN/THE BOSTON GLOBE/GETTY IMAGES (RED SOX)
JEFF CURRY/USA TODAY SPORTS (CARDINALS)
BEN MARGOT/AP (GIANTS)