Best record in 1-run games: Rangers reigning

Texas could set single-season mark in slimmest-margin wins

Best record in 1-run games: Rangers reigning

The Rangers not only boast the best record in the American League as August draws to a close. They're also making history in one way.

After an 8-7 walk-off win over the Mariners on Tuesday, the Rangers are a Major League-best 30-8 in one-run games -- a .789 winning percentage. But that's not just the top mark this season -- it would be the best single-season record in one-run games in baseball's modern era.

Since 1900, no Major League team has been better at scratching out wins than Texas this season. The Rangers have a chance to break the record set by the 2012 Orioles, who went 29-9 in one-run games (a .763 winning percentage) en route to an American League Wild Card berth.

The most amazing aspect of the Rangers' success in close games is that their bullpen has an AL-worst 4.72 ERA, but Texas makes up for it with its remarkable hitting in high-leverage situation. The Rangers have a Clutch score of 7.15, according to FanGraphs, where zero is average and 2.0 is considered excellent.

In short, Clutch score measures how much better or worse a player does in high-leverage situations than he would have done in a context neutral environment, and most players have a score somewhere between -1 and 1, suggesting that players usually perform as well in "clutch" situations as they do overall. Texas' score of 7.15 would be the fifth best since divisional play began in 1969.

As a result of the Rangers coming through when it matters most, they stand alone with a month of the regular season left to go. Here's a look at the other teams atop the list -- for now.

1. 2012 Baltimore Orioles (29-9 record in one-run games, .763 winning percentage)
The O's established the modern-day mark for the best record in one-run games during their surprising run to the playoffs -- 2012 was Baltimore's first postseason appearance since 1997, after 14 consecutive losing seasons. Pitching in so many close games, closer Jim Johnson led the Majors with 51 saves.

Once in the playoffs, the Orioles beat the Rangers in the AL Wild Card Game before falling to the Yankees in the AL Division Series in a deciding fifth game. Both of Baltimore's wins over New York in that series were by one run.

2. 1981 Orioles (21-7, .750)
Success in one-run games runs in the franchise: An earlier Orioles squad holds the second spot among the modern era's top five finishers. In a strike-shortened season divided into two segments, Baltimore missed the playoffs in 1981 after finishing second in the AL East in the first half and fourth in the second half, with an overall record of 59-46.

3. 1908 Pittsburgh Pirates (33-12, .733)
This Bucs team featured Hall of Famer Honus Wagner, who led the Major Leagues in batting average, on-base percentage, slugging percentage, hits, RBIs and stolen bases in the middle of the dead-ball era. Even with Wagner's .354/.415/.542, 201-hit, 109-RBI, 53-steal campaign, Pittsburgh finished second in the National League, missing the postseason despite a 98-56 record.

4. 1970 Orioles (40-15, .727)
The 1970 Orioles weren't just good in one-run games. They were dominant in all games, rolling to a Major League-best 108 wins during the regular season. The O's won the World Series while losing only a single game in the playoffs, erasing their loss to the Miracle Mets the year before. Two of their World Series wins had one-run margins.

With an offense led by Hall of Famer Brooks Robinson and AL MVP Award winner Boog Powell, and Hall of Famer Jim Palmer and Dave McNally atop the starting rotation, it was no surprise they were good in close games.

5. 1909 Pirates (33-13, .717)
The Pirates' one-run success wasn't enough to get them into the playoffs in 1908, but the next year, Pittsburgh was again historically effective at pulling out close games. This time, like the 1970 Orioles, the Bucs rode those wins to a World Series championship.

Wagner again put up league-leading numbers, and Pittsburgh beat Detroit in seven games in the World Series -- although the only game decided by one run was, ironically, a Pirates loss in Game 6.

David Adler is a reporter for MLB.com based in New York. Follow him on Twitter at @_dadler. This story was not subject to the approval of Major League Baseball or its clubs.