Cubs hope to improve Castillo's caught-stealing rate

SAN FRANCISCO -- Welington Castillo entered Wednesday ranked third among National League catchers in fielding percentage, but he's also tied for first in most stolen bases against, throwing out only five of 36 basestealers. There are other factors involved -- such as the timing of a pitcher's delivery -- but Cubs manager Rick Renteria said they're working with Castillo on improving his numbers.

"We've had some plays where runners should've been out and they weren't because we probably had a dropped ball or missed tag or something of that nature," Renteria said. "We have to take it all into consideration. Do I think he's throwing the ball well? Yes. Is he able to better his numbers over the long haul? Probably."

On Tuesday night, Renteria considered challenging a call at second base in the fifth when the Giants' Angel Pagan was ruled safe on a stolen base. Shortstop Starlin Castro didn't seem to get his glove down for the tag.

"It's instinctual for an infielder to try to tag the runner, to chase the runner," Renteria said. "We talk about straddling the bag and taking the tag to the ground, which gives you a better chance to get the foot or hand."

Renteria said they don't want the pitchers to change their delivery in an effort to stop potential basestealers.

"The reality is a lot of pitchers don't worry about the stolen base because they feel they can go ahead and get the hitter," Renteria said. "If I want to make it an issue, then I'm taking away from the pitcher's ability and focus and doing what he needs to do against the hitters. I don't want to do that."