There is plenty of math in baseball. Here are some fun numbers for Giants fans to contemplate:

If the Giants merely go 8-9 to finish the season, the Dodgers must go 15-4 to tie them atop the NL West standings. Oh yeah: And the Dodgers have a home series coming up with the wild-card jousting St. Louis Cardinals, followed by a road trip with stops in division-leading Washington and Cincinnati.

Or if you prefer the neat and tidy version: The Giants' magic number is 13.

They took one more step toward their second NL West title in three seasons and their ninth since moving to San Francisco, beating the Colorado Rockies 8-3 behind Tim Lincecum in yet another thumper at Coors Field Wednesday night.