Here's an interesting post from Systat (he posts on rx and has been sharp on totals):
System for the SF/COL game...
Under is 20-1 in last 21 national league games with totals lower than 7 if the combined ERA of starters is lower than 5.98. Average of total runs scored in those games is 4.33. Under prevailed in all 4 home SF games during this streak including three games where Lincecum was the starter. The only over had 7 runs scored and happened when Colorado with Jimenez traveled to SD earlier this season. Jimenez allowed only 1 run and 4 hits in 7 innings of work in that game, including 13 strikeouts and the 7th run came in the bottom of the 9th when Rockies had a 5-1 lead. All in all the bullpen was responsible for 3 of 7 runs scored in that game and the 7th run was scored with two outs in the bottom of the 9th on a single that scored a runner who was on the 2nd base only because of the fielder's indifference that happened seconds ago. Hopefully we will be luckier than that tonight.