The Arizona Diamondbacks have scored first-inning runs in five of their first seven games, and they are off to a 5-2 start that puts them atop the National League West. They have tallied a major league-high 10 first-inning runs while allowing opponents three for a first-inning run differential of +7.

That first-inning run differential also tops the majors. As important as bullpens are in today’s game, scoring early can be equally critical to winning. To reduce the effect of one big inning this early in the season, here are the leaders in run differential over the first two frames in 2008.

Run Differential in Innings: 1-2, 2008

Team. . . . . . . . . . . . . . . . . RS. . . . .RA. . . . Diff. . . . . . .Record
Oakland Athletics. . . . . . . . . .8. . . . . 1. . . . . .7. . . . . . . . .3-4
Arizona Diamondbacks. . . . . .12. . . . . .5. . . . . 7. . . . . . . . . 5-2
Milwaukee Brewers. . . . . . . . 8. . . . . .2. . . . . 6. . . . . . . . . 5-1
St. Louis Cardinals. . . . . . . . . 6. . . . . .0. . . . . 6. . . . . . . . . 5-2
San Diego Padres. . . . . . . . . 11. . . . . .5. . . . . 6. . . . . . . . . 5-3

The only team with a losing record on the list is Oakland. The Athletics, however, have managed to score in the first inning only twice this season -- including three times in Saturday’s 6-1 win over Cleveland -- and the A’s pen has absorbed a blown save and a pair of losses.

The surprising St. Louis Cardinals also make the list. The Cards look like one of the weaker teams in the NL Central, but they are off to a fast start with a 6-0 scoring edge in the first two innings.

A year ago, the Cardinals endured a disappointing season as the defending World Series champions. The club also finished last in the NL in first-inning run differential at -46.

The teams with the best first-inning run differential in 2007? Three division winners tied for that honor. The Boston Red Sox, Los Angeles Angels and Chicago Cubs each scored 41 more runs than they allowed in the first inning to lead all clubs.