Rhodes will might have more saves if Oakland can manage to score enough runs, but I'll pick Chacon to have a lower ERA, WHIP, and more K's. I know nobody is going to agree with me, but that's fine.
Last season Oakland only had 6 more save opps than Colorado, but Oakland also doesn't have arguably their best hitter this season. Given the same amount of save opps, it will be close between Chacon and Rhodes, but I'll take Chacon.
"Jack, will you call me, if you're able?"
"I've got your phone number written, in the back of my Bible."