On the surface, Game 2 of the World Series was an almost immaculate pitchers’ duel won, 2-0, by Giants lefty Madison Bumgarner over the Tigers’ gutty Doug Fister, who allowed only one run despite being hit on the head by a line drive that landed 100 feet beyond second base.

That’s the surface. Underneath was a larger trend, going back decades. This was probably a game — the game — that Detroit absolutely had to win to capture this World Series. Now, they are down two games to none, which hardly seems impossible to overcome. Yet for more than 35 years it has, in fact, been an almost insurmountable obstacle.

The comforts of such a lead are apparently enormous, primarily because the team in the Giants’ position knows that it will get to come back home for a Game 6 at the least. That seems to relax almost every team as it takes to the road, playing as if those hostile games are just house money. In the last 30 years, 13 teams have been in the Giants’ current position. Every one has won the World Series, including famous upsets or sweeps.

In fact, that’s the formula the Giants themselves used to beat favored Texas in just five games two years ago. It’s beginning to appear baseball’s decision to let home-field advantage in the World Series be decided by the All-Star Game now may carry more weight than the game intended.

The American League has, beyond debate, been the stronger circuit in head-to-head play in recent years, often by embarrassing margins. Yet the National League has won the last three all-star games and now is in excellent position to stun another AL favorite in the Series.

Patterns change. But for those who chase the World Series every fall there is a flow to these seven-game battles, and a 2-0 lead with the certainty of a conclusion on your own field seems to be an enormous incentive and cushion for the front-runner. Also, every mistake by the team in the Tigers’ position feels like the beginning of the end of their postseason world.

That San Francisco has already beaten the Tigers’ ace, Justin Verlander, only doubles down their confidence. The Giants’ red-hot Ryan Vogelsong is slated to start Game 3 while ace Matt Cain is set for Game 4. And now it appears that Bumgarner, a World Series hero in 2010, has fixed a mechanical glitch that’s made him miserable for the last seven weeks. On this cool, gorgeous Thursday night, he made Detroit suffer.

Teams like the 1978 Yankees and ’81 Dodgers are the last to contradict this trend. It’s been a long time. But the Tigers dominated and swept the 95-win Yankees, so if anybody has the thump to do the job, maybe it’s them.

This Game 2 was just the kind the pitching-first, situational-hitting game that the Giants love to play in their pitcher’s paradise. There’s lots of fine pitching and dicey strategy — when to send a runner home, when to play the infield back and such. But a very few points proved to be the keys.

First, Bumgarner had been awful for seven weeks, butchering his last seven starts of the regular season, then getting bombed by both the Reds and Cardinals in playoff losses that actually knocked him out of the Giants’ rotation in favor of Barry Zito for Game 5 of the NL Championship Series. Giants fans anticipated this game like a trip to a hungover dentist.

“I think we’ve got it fixed,” Bumgarner said Wednesday of the problems in his delivery that were making him cut himself off with an incomplete finish to his delivery. “But there’s no way to tell until you get out there.”

The answer was fast in coming. From the very first inning, he had his best and sharpest stuff, fanning the tough-to-whiff Omar Infante in the first inning on three pitches — a fastball, a slider and a change-up. Note to Tigers: Get ready for a long night’s work.

Later, the Giants cut down gargantuan Prince Fielder trying to lumber all the way from first to home on a Delmon Young double, thanks to a gorgeous double relay from Gregor Blanco to Marco Scutaro to Buster Posey — 320-feet of rope-like pegs from the left field corner to home plate that may not have taken three seconds.

Third base coach Gene Lamont probably killed the Tigers’ best chance for a big inning, sending Fielder when Detroit would have had men on second and third base with no outs. “Gene was just a little over-aggressive,” Tigers Manager Jim Leyland said. “We haven’t been scoring many runs lately. . . . The ump made an absolute great call in a tough situation.”

In the final piece of inside baseball, Leyland decided to concede a run in a 0-0 game, playing the infield back with the bases loaded and none out in the seventh inning. Even though the Giants grounded the ball directly to second base, the Tigers had already made their bed — two outs on a double play traded for one run — and then had to lie in it. They were behind, 1-0. That never changed. An insurance run, a Sergio Romo save and their night was done.

“We were absolutely thrilled to get out of that inning with just one run,” Leyland said. “No, it’s not debatable to me.”

In many past World Series, road teams in the Tigers’ position sometimes didn’t seem to understand the urgency of escaping with a split. That wasn’t the case this time. The Tigers, especially Fister, truly did compete like the series was on the line. In the second inning, Blanco ripped a line drive back at the 6-foot-8 Fister that hit the pitcher on the right side of his head, perhaps an inch above the ear. As the crowd gasped and Fister crumpled to one knee, the ball ricocheted high in the air and landed 100 feet behind second base.

To universal disbelief, Fister acted as if nothing at all had happened. He didn’t even take off his hat to check his hair. He walked the next man to load the bases then got Bumgarner to pop up.

Thus Fister became the first pitcher in World Series history to escape a bases-loaded jam and a fractured skull in the same inning. Then he retired the next dozen Giants hitters in a row.

“I was scared to death when it happened,” Leyland said. “But he was fine. They were asking him all kinds of questions [on the mound]. He was saying, ‘San Francisco,’ ‘second game.’ It was almost funny he got the answers [so fast]. He was pretty blase about it.”

Nonetheless, Leyland watched him closely. “You never know if there’s a later reaction. Maybe an hour later you have a bad headache and that puts a different light on it.”

Apparently, Fister’s biggest headache will be that, after pitching six scoreless innings, he was lifted after a leadoff single by Hunter Pence, who eventually scored the game’s first run. That made Fister both a hard-luck and a hard-headed loser.

On the surface, this was a neat, compact Giants win on the heels of the Verlander dusting. It seems like it ought to be just the beginning of a long, fine World Series. Yet there is reason to believe — 13 reasons, actually — to suspect that it was much, much more.

For previous Thomas Boswell columns, visit washingtonpost.com/boswell.