SAN DIEGO -- With every outing, a young pitcher learns something.

It might be about himself. Could be about the opponent. Might even be about how a ballpark plays.

Joey Estes entered perhaps the best laboratory baseball has to offer these days during the Athletics' 6-1 loss to the Padres on Monday night at Petco Park. The 22-year-old right-hander had three matchups against MLB batting leader Luis Arraez.

Arraez isn’t just a tough out; he’s the toughest of outs. He’s a throwback, turning his bat into a wand to put just about any pitch anywhere into play -- or at least to extend an at-bat by fouling off two-strike pitches until he gets one he can handle.

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Estes took the loss after allowing three runs across five innings, a step back after he brought a perfect game into the seventh inning in his previous start. But Estes was up to the challenge against Arraez.

Estes retired Arraez three times. Arraez has faced a starting pitcher three times in a game 58 times this season; only 13 times has he gone 0-for-3 against one pitcher.

“This is the best offense in baseball right now, in terms of batting average,” A’s manager Mark Kotsay said. “They’re seventh best in OPS. They do a lot of things right. For him to go five innings, give up only three runs and handle Arraez at the top -- Arraez took some great at-bats, don’t get me wrong -- but I thought Joey did a great job of keeping the ball down in the zone, not giving in to him.”

Here’s a look at the three battles:

First inning
Arraez leading off, so no outs, nobody on
0-0: Fastball away, ball
1-0: Fastball, inner half, fouled off
1-1: Fastball up on the outer corner, lineout to left field

“It kind of all changes, depending on how I feel hitter to hitter,” Estes said.

Second inning
Two outs, bases loaded
0-0: Slider in the dirt, ball
1-0: Sweeper high in the zone, called strike
1-1: Fastball away, flyout to left field

That last pitch, spotted well, ended the inning. Estes began to walk off the mound casually, but eventually showed his emotion and pounded his fist into his glove before reaching the dugout.

“There’s a lot that goes into it when a hitter’s up and why I’m throwing that pitch,” he said. “It’s one of those things -- what you’re feeling in that moment.”

Fourth inning
Two outs, runner on second
0-0: Changeup at the top of the zone, called strike
0-1: Changeup away, foul
0-2: Fastball high, ball
1-2: Fastball high, fouled off
1-2: Slider low in the zone, lineout to first base

The foul-off was classic Arraez. The pitch was 4.26 feet high, per Statcast, above catcher Shea Langeliers’ helmet. Yet Arraez got a bat on it and fouled it back. The next pitch was the only ball Arraez hit hard off Estes (96.6 mph exit velocity), but it found Tyler Soderstrom’s glove.

“We had a plan,” Estes said. “I threw two really good changeups. Then a fastball above eye level, and he still gets bat to ball. Then we change eye levels and go down [with the slider], and he still gets to it. Great hitter.”

Arraez has two batting titles to attest to that, and might be on his way to a third straight. But Estes came away knowing he can compete with the best, even on a night he might not be at his best.

“No matter what the results were today, I learned a lot about myself, about how I threw the ball in general,” said Estes, who has only eight Major League starts under his belt. “These are games when you learn. You put that away and go into the next start and, hopefully, get the results.”