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6/16/2014 1:50 P.M. ET

Hudson continues to defy age

Veteran starting pitcher thriving at 38 years old; leading Major Leagues in ERA

Tim Hudson is 28 days away from his 39th birthday, which means he's 393 days away from his 40th birthday, which means he really has no business sporting the best WHIP, FIP or walk rate of his career.

And oh yeah, Hudson probably shouldn't have the Major League's best ERA (1.81), either.

But going into Wednesday's start at U.S. Cellular Field against the White Sox, this is where Hudson stands. And when you remember what happened 11 months ago, when the poor guy couldn't stand on his own right ankle, it's all the more amazing.

Even if you saw Hudson as a potentially shrewd signing on the part of the Giants this past winter, you probably didn't expect them to get this much immediate return on their two-year, $23 million investment. Hudson, with 2,813 innings under his belt, was supposed to round out San Francisco's staff, not necessarily lead it. His impactful presence on all those who cross his path in a big league clubhouse was supposed to be a perfect addition to a club with both a championship culture and championship expectations.

But an adjusted ERA 87 percent better than league average? That's better than the Giants bargained for, and it's a testament to the constant movement Hudson still gets on his pitches at this late stage of his career.

"His stuff is so good," catcher Buster Posey said, "that he's able to get away with mistakes other people can't."

Exactly. Hudson's game isn't about defying age; it's about channeling gravity.

It's about summoning the game's great equalizer -- the ground ball -- at a time when strategic defensive data has made the sinker sexier than ever. And pitching his home games at AT&T Park doesn't hurt, either.

"My game is pretty simple," Hudson said. "I'm just trying to throw good stuff in the bottom of the strike zone."

Doesn't get simpler -- or more effective -- than that. Per BrooksBaseball.net, Hudson has thrown roughly 63 percent of his pitches this season either in the lower third of the strike zone or below. And so, of the balls put in play against him, 57.4 percent have been ground balls. Per FanGraphs, Hudson has thrown 44 percent sinkers, 24 percent cutters and 15 percent splitters, and all those pitches generally move in one direction.

Down, down, down.

"I don't think there's any secret to what I do when I'm out there," Hudson said. "I think people have a pretty good idea of what I'm going to do."

That might be so, but knowing what's coming and hitting what's coming are two very different things. The late movement leaves hitters flailing and chasing at pitches in and out of the zone, and the contact made is often of the weak variety.

Hudson has steadily incorporated the split-finger fastball -- a pitch that gets the hitter to start his swing as it barrels to the strike zone before bottoming out at the last second -- into his repertoire more and more in recent seasons, and that's only assisted his side of the guessing game between pitcher and hitter. He is getting hitters to chase pitches out of the strike zone 31.6 percent of the time.

"He's a good athlete and can handle the bat," Posey said. "And I think him being a good athlete helps him read hitters really well. So it's fun to have that continuous dialogue with him leading up to the game and then making those adjustments in the game."

Hudson's ability to adjust is what has made him competitive even on those rare days when the ball isn't moving the way he'd like it to. You don't compile a 65.1 winning percentage (the 23th best of all time, per Baseball Reference) in your career without gutting your way through some would-be clunkers. Case in point: In a June 7 start against the Mets, Hudson lasted just five innings on account of allowing a season-high nine hits and three walks, but he limited the damage to three runs and put the Giants in position to rally late.

"Some days, it's a little bit of a struggle for you," he said. "But on those days where you struggle, that's where you hope those other intangibles kick in. Instead of giving up a seven- or eight-spot, you keep it at four or five and hopefully give your team a chance to win."

Hudson has given the Giants that chance every time he has taken the mound this season. In his two losses, he allowed a combined three earned runs over 15 2/3 innings. And in a season in which Matt Cain, Tim Lincecum and Ryan Vogelsong have been a bit below the statistical averages, Hudson's arrival has been instrumental in San Francisco's surge to the top of the National League West standings.

Hudson doesn't have the most electric stuff, the freshest birth certificate or the most hair of any NL starter. But nearing the halfway point, he's been the best of the bunch, building a strong case to start next month's All-Star Game, while padding his Hall of Fame credentials, too.

You've got to love gravity.

Anthony Castrovince is a reporter for MLB.com. Read his columns and follow him on Twitter at @Castrovince. This story was not subject to the approval of Major League Baseball or its clubs.