Dodgers, Astros: World Series ball slicker than regular-season ball

— -- The baseballs used during the World Series are slicker than the ones used during the regular season, pitchers and coaches from the? Dodgers and Astros?said Saturday night. The difference, they told Sports Illustrated, is in the grain of the leather, making it particularly difficult to throw a good slider.

"We had a well-pitched game [Saturday night] from both sides," Astros pitching coach Brent Strom told SI, after losing to the Dodgers 6-2 in Game 4. "Why in the world would the baseballs in the World Series be different? Because you can see the difference. You can feel it. I don't understand it at all."

The World Series balls are tested during manufacturing and made from the same materials as baseballs in the regular season, MLB senior vice president of baseball operations Peter Woodfork told SI. "The only difference is the gold stamping on the baseballs," he said. Blue ink is used during the regular season.

An MLB source told SI that the way the baseballs were treated with pregame rubbing mud before Game 4 could be the reason for the perceived difference.

Dodgers pitching coach?Rick Honeycutt told SI that Game 3 starter Yu Darvish "noticed the difference."

"He told me the balls were slicker and he had trouble throwing the slider because of how slick they were. He wasn't able to throw his slider the same way."

According to SI, Cleveland Indians staff members said during the ALDS that the balls felt different than the regular-season balls. As with the World Series balls, LDS and LCS balls are also stamped with different ink and logos.

Astros Game 4 starter Charlie Morton told SI that pitcher Lance McCullers took a "blindfold test" and "could tell which ball was which with his eyes closed. It's that different."

"The World Series ball is slicker," said Astros pitcher Justin Verlander. "I noticed it especially throwing a slider. It didn't feel the same. The home run I gave up to [Joc] Pederson was a slider."

Verlander threw 17 sliders in Game 2 and got only one swing and a miss -- the fewest swings and misses on his slider in his 36 starts this year of more than two innings.

Darvish lasted 1? innings in Game 3. He threw 14 sliders and didn't get one swing and a miss, for the first time in 34 starts this year.

Astros right-hander Ken Giles is having the hardest time with his slider. During the season, he threw a slider 47 percent of the time, holding batters to a .133 average. But during the postseason, Giles only threw two sliders -- both balls -- among his eight Game 4 pitches. Giles threw his slider out of the strike zone 51 percent of the time during the regular season, but in the postseason, he has missed 74 percent of the time.

"I know guys have been talking about the ball," Honeycutt said. "I also know that MLB has been talking for a while about maybe a ball that's more like the ball in Japan, where the leather is tackier so that you can use it right out of the wrapper. I think something has to be done."

The rate of home runs has risen 35 percent in the World Series, after a regular season that set a record with the most home runs of all time (6,105). Fifteen home runs have been hit so far in this World Series. Of the previous 112 World Series, only eight had more.

Game 5 is Sunday night at Houston, with the series tied 2-2.