How SF Giants’ Rodríguez turned new slider grip into first All-Star selection

SAN FRANCISCO — Randy Rodríguez didn’t need to tweak his slider. The pitch was performing well; Rodríguez was, too. But as April gave way to May, Rodríguez didn’t like the state of the pitch. There wasn’t anything wrong with it, but he wanted something different, something bigger.

That pursuit led him to Ryan Walker. With the help of the Giants’ crossfiring right-hander, Rodríguez will soon be traveling to Atlanta to experience the first All-Star Game of his career.

“As soon as he got on the mound, it is what it is now,” Walker said. “It’s kind of unbelievable.”

Rodríguez, 25, has transformed into one of baseball’s most valuable relievers. By WAR, he has been the most valuable reliever in the game. Entering Monday, he leads all relievers in ERA (0.69) and FIP (1.34). He’s raised his strikeout rate. He’s slashed his walk rate. It’s rare for a middle reliever to earn an invitation to the Midsummer Classic, but Rodríguez was too elite to deny.

The right-hander only has one save, but manager Bob Melvin consistently calls upon him to play the role of fireman. On Saturday, for example, Melvin called on Rodríguez with two men on and two men out to face Jacob Wilson, who will start at shortstop for the American League All-Stars. Rodríguez, as he’s done all year, doused water on the rally by getting Wilson to pop out.

Rodríguez showed flashes of excellence last season as a rookie. The stuff was there, particularly with his four-seam fastball and slider, but he was marred by inconsistent command. In the coming days, he’ll head to Atlanta with Logan Webb and Robbie Ray to represent the Giants among the game’s best and brightest.

“It’s been probably one of the bigger stories in Major League Baseball that a lot of people aren’t really paying attention to from last year to this year,” said bullpen coach Garvin Alston in mid-June. “Even his ascension being in the minor leagues and trying to figure it out and walking a lot of guys to now just absolutely dominating the zone. It’s been great to watch.”

It’s a career year that’s been made possible due in large part to Rodríguez’s will to change.

By the end of April, Rodríguez established that he was in the midst of a breakout season. He didn’t allow an earned run in his first 11 relief appearances of the year, totaling 16 strikeouts with no walks. The right-hander’s first true mistake of the season arrived on April 29 when he allowed a two-run homer to Xander Bogaerts on a slider that caught a little too much zone.

Despite the homer, there wasn’t a pressing need for Rodríguez to change his slider. Opponents were hitting .182 against Rodríguez’s slider at the time. But Rodríguez wanted a slider with bigger movement. He wanted a slider like Walker’s, who learned his slider grip from Alston two years ago.

So, he asked.

“He literally said, ‘How do you throw your slider?’” Walker recalled. “I showed him. Then, he took that out to catch play. Then literally, as soon as he got on the mound, it is what it is now. It’s kind of unbelievable.”

“We did a bullpen — a little touch and feel — and the first one he threw was incredible,” Alston said. “I was like, ‘Oh, wow.’”

Rodríguez’s revamped slider generated considerable horizontal break during that first bullpen session, moving more like a traditional sweeper. But when Rodríguez unveiled his new slider in a game only days after picking it up, he threw the pitch with an unforeseen power and force that combining sweeping movement with hard velocity.

“People wouldn’t consider -13, -15 (inches of horizontal movement) not a big sweeper, but at the velocity, I was like, ‘We got something here,’” Alston said. “It feels good to him, it feels natural to him.”

“It’s not like a Jacob Junis, 82-mph sweeper where it takes a left turn,” said pitching coach J.P. Martinez. “The shape is sweepy but it’s firm. It’s actually kind of similar to John Brebbia’s — but plus five miles per hour.”

In April, Rodríguez’s average slider clocked in at 85.3 mph with roughly seven inches of horizontal movement. In May, he was up to 86.4 mph and 10 inches of horizontal movement. In June: 87 mph, 12 inches of horizontal movement. There have even been instances where Rodríguez has picked up as many as 17 inches of horizontal movement, such as with his strikeout of the Padres’ Jackson Merrill in early June.

While Rodríguez uses a sweeper grip, Baseball Savant categorizes the pitch as a slider since it doesn’t have the bigger, slower movement of traditional sweepers. Rodríguez, himself, still considers the pitch a slider.

“To me, it’s just a slider,” Rodríguez said through team interpreter Erwin Higueros. “I know the metrics may call it a sweeper, but to me, it’s just a slider.”

What’s especially fascinating about Rodríguez’s slider is how he’s learning to manipulate the pitch based on what he needs in a given at-bat. If Rodríguez throws the sweeper a bit softer, he can generate more horizontal movement; if he throws it harder, he’ll get tighter movement that’s in the 88-90 mph range.

Rodríguez isn’t yet able to manipulate the pitch at will, but there have been variations in how the pitch moves. Here are two different examples (both in June) of how Rodríguez’s sweeper can operate.

This sweeper to strike out Carlos Narváez clocks in at 88.3 mph with 10 inches of horizontal movement.

This one to strike out Michael Harris II, by contrast clocks in at 85.9 mph with 16 inches of horizontal movement.

“For him, when he wants to throw this for a strike, he’ll back off just a little bit. When he backs off, it’s a little bit bigger, but then it lands in the strike zone,” Alston said. “When he’s throwing the swing-and-miss one, he throws it harder, and now it gives the appearance of a fastball and gets guys going a little earlier. Although it’s a smaller break, it’s still big enough to get a lot of swings and misses.”

Said catcher Patrick Bailey: “The shape’s kind of more like a sweeper, but he’s throwing it in the upper 80s. I think he’s thrown some at 90. As long as the velo is up with the shape, the results speak for themselves.

Regardless of the specific speed or movement, opponents have been unable to hit Rodríguez’s revamped slider. Since May, opponents are hitting .159 against the pitch with a .205 slugging percentage.

Along with the slider, Rodríguez’s four-seam fastball is also generating roughly an inch-and-a-half more vertical movement compared to last season. Rodríguez’s arm angle on the fastball is slightly higher compared to last year (37 degrees in ‘24, 39 degrees in ‘25), but Martinez attributes the additional vertical movement to Rodríguez throwing with more intent.

“He’s one of those guys when he’s throwing at a lower intent, his slot and fastball profile will be a little different than when it’s cranked up all the way to 99, 100 miles an hour,” Martinez said. “To see the strikes and the profile and the confidence all come along, it’s been awesome.”

Rodríguez’s breakout is all the more astonishing given that he’s only using half of his repertoire.

The right-hander has exclusively used his four-seam fastball and slider this season, but the Giants’ pitching brass maintain that he’s a four-pitch pitcher. Currently residing in hibernation is sinker and changeup, a pair of pitches that he threw roughly six percent of the time last year.

Rodríguez still throws those pitches during catch and bullpens, but hasn’t needed those other two offerings. But Rodríguez knows that hitters — namely those in the NL West — will see him multiple times. When the time comes, he’ll deploy those other offerings.

“He’s a two-pitch guy right now — and that second pitch has changed — but really in essence, he’s a four-pitch guy when we need him to be,” Martinez said.