SAN FRANCISCO -- Solid pitching was not nearly good enough for the Rockies on Monday night.The Rockies' inability to do significant damage despite their four hits and five walks in six innings against Giants starter Madison Bumgarner ultimately led to a 2-1 loss to the National League West leaders at AT&T Park. The victory reduced the Giants' magic number for winning the division to eight -- combination of Giants victories and losses by the second-place Dodgers. The result also left the Rockies (58-88) needing to win 10 of their final 16 games to keep from exceeding their club record for losses in a season, 95 in 1993 and 2003. At least the recent slide toward the futility record is different from the first half, when the issues could be blamed on poor pitching. This time, starter Jhoulys Chacin held the Giants to one run and five hits in five innings -- actually outpitching Bumgarner (15-10), who struck out six in six innings but wobbled often. Relievers Guillermo Moscoso (3-2), who overcame three hits and a run to open the sixth, Edgmer Escalona and Josh Outman accounted for themselves well. But as has been the case too often lately, small failures led to a loss. Nine of the Rockies' last 12 games have been decided by one run. Of those single-run decisions, the Rockies have prevailed just once. "You go back to our Atlanta-Philadelphia trip, the three-game series we played against the Giants at home and the previous three-game series at San Diego," Rockies manager Jim Tracy said. "These young people, they're going to make mistakes. We know that. "It's never good to lose, but when you have young people in games like this, there's one learning point there -- the fact that little miscues, whether mental or physical, can lead to costing you games like this." Several offensive opportunities eluded the Rockies. A key one occurred in the first, when Dexter Fowler drew a leadoff walk but was thrown out by catcher Buster Posey on a steal attempt. Tracy protested the call to no avail. Jordan Pacheco's double with two out would have scored Fowler. "That was a momentum changer," Bumgarner said. "There's no telling what would have happened [without Posey's throw]. I was trying to battle and get out of there, and that was a big play. "My mechanics were probably as bad as they were all year. I was just trying to battle and just keep battling every inning, and I was fortunate to make pitches when I needed to and get out of it." Bumgarner forced DJ LeMahieu into a double-play grounder to end a second inning that began with a Chris Nelson walk and an Andrew Brown single. With runners on first and second and one out in the third, Giants shortstop Brandon Crawford ranged far to his right and threw out Pacheco at first, then Bumgarner fanned Rosario. The Rockies' only run came in the fifth, when Chacin doubled and scored on Josh Rutledge's two-out triple. One of the Giants' runs scored on a Chacin pitch that eluded catcher Wilin Rosario for his Majors-leading 20th passed ball of the season. Crawford had tripled to open the third and scored with one out. Considering the second out of the inning was an infield grounder that might not have scored the run -- since the Rockies would have been playing with a drawn-in infield -- the miscue proved costly. Rosario leads the Rockies with 24 home runs, but his defense is an issue. Passed balls played a role in runs that scored in three of the recent one-run losses. "The defensive side of things is vitally important in games like this," Tracy said. "To think that every time you get an opportunity you're going to score is a complete misnomer for any of 30 teams in baseball." Chacin was bailed out of another possible run when left fielder Brown threw to the plate to nab Crawford, who was trying to score from second on Angel Pagan's single. However, Chacin has done quite well on his own. He has held his opponent to zero or one run in five of his six starts since coming back in late August from a nerve injury in the right side of his chest, which had kept him out since the beginning of May. "I didn't have my best command today, but whenever I had to make my pitch, I made my pitch," said Chacin, who said he might pitch this winter in Venezuela to build his innings count, if the organization gives him the OK. "But they played good defense, and that's why they won the game. We couldn't score a run whenever we got a chance."
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.