49ers' quarterbacks in victory and defeat

2012 Starting QBs: 49ers Victories

Colin Kaepernick and Alex Smith have combined for 18 touchdown passes with three interceptions as starting quarterbacks in the San Francisco 49ers' 10 victories this season.

Both posted NFL passer ratings above 110 across those games. Their Total QBR scores for those games were nearly identical: 80.9 for Kaepernick and 79.5 for Smith.

Each quarterback has also lost two games as a starter. Neither has been as good in those games. The numbers say Smith was quite a bit worse than Kaepernick in defeat, particularly when he threw three interceptions during a 26-3 home defeat to the New York Giants. However, Kaepernick's QBR score in defeat was inflated some because play-by-play data counted the quarterback's fumbled pitch against the Rams as an aborted play, sparing Kaepernick from a fuller share of the blame.

There aren't enough snaps in defeat -- or perhaps in victory, either -- to draw hard conclusions about each player.

I do think it's interesting, at least, to see how the numbers break down.

The first chart shows the numbers for each quarterback as a starter in the 49ers' victories.

Kaepernick started victories against Chicago, New Orleans, Miami and New England.

2012 Starting QBs: 49ers Defeats

Smith started victories against Green Bay, Detroit, the New York Jets, Buffalo, Seattle and Arizona.

One big difference so far has been Kaepernick's ability to avoid sacks. Smith sometimes held the ball too long, as if he were willing to take a sack if it meant lowering the risk for a turnover. His sacks taken as a percentage of dropbacks has been at 9 percent or higher in victories and defeats. The percentage for Kaepernick has been at 5.5 or lower regardless of outcome.

Kaepernick has also made game-changing gains with his legs. He had a 50-yard scramble to the St. Louis 14-yard line during the final minutes of regulation while the score was tied, 10-10.

The 49ers lost that game, but that run gave them something they never had late in the defeats Smith started -- a real chance to win.

Kaepernick struggled to a season-low 27.8 QBR score against Seattle on Sunday night. That game slipped away from the 49ers for reasons related and unrelated to Kaepernick. The deficit was 28-6 at halftime, rending Kaepernick less relevant to the outcome for much of the game.

The charts exclude either quarterback's stats for the game San Francisco tied with St. Louis in Week 10. Smith started that game. Kaepernick finished it. Nobody won it. None of Kaepernick's other stats off the bench factored into the charts.