When is a season truly lost? If you had asked fans of the Oakland Athletics and the Houston Astros that question at the end of May, a point at which both teams found themselves marching through nightmare seasons with no hope in sight, the answer would have been “right now.”

The A’s hit their low point on May 29 in Cleveland, the traditional home of low points. After dropping a 6-2 decision to the Indians, Oakland’s record stood at a putrid 17-32, which left them 12.5 games back of the Angels in the AL West, 12 games back in the wild-card standings.

The Astros had found their nadir five days earlier in Chicago, where the Cubs knocked them off 4-2, dropping the Astros record to 15-30 – 14 games back of St. Louis in the NL Central and 11.5 games behind in the wild card.

Oh, how things have changed. Oakland has won 47 of its last 62 games, climbing into a tie with the Angels at the top of the AL West, with a four-game lead in the wild card. Meanwhile, the Astros have gone 44-21, bringing them all the way up to a 1.5-game lead in the NL wild-card race. Just over two months after having slightly less than a snowball’s chance in hell, both teams are odds-on picks to make the playoffs.

What we’ve seen here, simply put, are two of the greatest turnarounds in baseball history. Usually, by the time you’ve found yourself 15 games under .500, you’re guaranteed to be doing home improvement jobs in October, not playing for a ring and a champagne shower. In fact, in all of major league history, only one team, the 1914 “Miracle” Boston Braves, fell further than 15 games under .500 and still made it to the postseason. In fact, just nine teams have ever been 10 or more games under .500 and still made the playoffs.

How have the A’s and Astros gotten back into the playoff chase? It’s not that hard to see, really. To play as poorly as these teams did earlier in the year, almost everything had to go wrong; to play as well as they have recently, almost everything has had to go right.

The A’s have been a middling offensive team for the past several seasons (ninth in the AL in scoring in both 2003 and 2004). Currently, the team finds itself fourth in the AL in scoring, trailing only the bomb squads in Texas, Boston, and New York. At the end of May, they were 13th in the league in in this category, but they’ve led the majors in scoring since the first of June.

That offensive production has come from some familiar faces. Third baseman Eric Chavez – who boasted a .214 BA/.276 OBA/.317 SLG line at the end of May – has finally located his stroke, hitting .324/.380/.577 since, and 2004 Rookie of the Year Bobby Crosby has amassed 70 hits in 60 games and an on-base average of .361 since coming off the disabled list at the end of May.

But the offensive story in Oakland has been rookie first baseman Dan Johnson. Since being called up on May 27, Johnson has hit .321/.405/.546 in only 227 plate appearances. Along with fellow rookie Huston Street – who’s established himself as one of the best closers in the game with a 1.31 ERA and 50 strikeouts in 55 innings of work – Johnson rates as a favorite for AL Rookie of the Year.

It’s been more than just Johnson and the rest of the revitalized A’s offense that’s led to Oakland’s success. In the A’s first 49 games, their starting pitchers had a 6-25 record, with a 4.94 ERA. In the 61 games since, they’re 38-12 with a 3.27 ERA. The improvement has been due mostly to a boost in strikeouts and a slashing of walks by over one per nine innings as a group, going from a 1.51 K/BB ratio before May 29 to a 2.35 K/BB ratio since. Dan Haren and Joe Blanton have improved the most – Haren has gone from walking over four batters per nine innings to walking just over one batter per nine, while Blanton has gone from a 0.65 K/BB ratio to a 2.27 ratio.

Meanwhile in Houston, pitching and defense have been the stories all year. The Astros have only allowed 423 runs on the season, making them the stingiest squad in all of baseball. Meanwhile, the top of the starting rotation – Roger Clemens, Roy Oswalt, and Andy Pettitte – has been simply astonishing, allowing a microscopic 2.46 runs per game.

Which is a good thing, because Houston’s offense still isn’t much to look at. They’re 14th in the NL in scoring with 468 runs, and clearly feeling the loss of Carlos Beltran and Jeff Kent.

This year’s team was slow in picking up the slack, but are clearly coming around. A pleasant surprise has been third baseman Morgan Ensberg, who has followed a mediocre 2004 with a scorching 2005, hitting .290/.385/.582. Lance Berkman’s return to form and Craig Biggio’s continued defiance of father time have been just enough to complement the team’s lights-out pitching. The Astros are 13th in the NL in scoring, but that’s up from 16th (and last) in the league at the end of May – just enough offense to turn those losses into wins.

Is it reasonable to expect both these teams to keep playing as well as they have over the past two months? Of course not. As mentioned earlier, to play as well as they have, almost everything has to go right, and that’s not likely to keep happening over the season’s final two months. Injuries or slumps are bound to hit, as is the nature of the game.

But both of these teams are still good enough to not only make the postseason, but to be contenders once they get there. Is there any team in the AL who wants to face a revitalized Barry Zito (10-2 with a 2.72 ERA in his last 13 starts) and Rich Harden (7-1, 2.27 ERA in nine starts since returning from the DL) in a short series? The same goes for the Astros, who would be thrilled to start Clemens, Oswalt, and Pettitte in a five-game series.

The Astros have no chance of catching the Cardinals, who are out in front by 10 games in the NL Central. But in a weak National League, where everyone seems to be in a race toward .500,the Astros are solid contenders for the wild card, with only the runners-up in the NL East to worry about. Meanwhile, the A’s kick off a series in Oakland against a reeling Angels team today, with first place in the AL West at stake.

If the 1914 Braves were a miracle, then we’re seeing two more this year. Those Braves capped their amazing run by sweeping the heavily favored Philadelphia A’s to win the World Series. As unlikely as it seemed two months ago, the Astros and A’s might just have a chance to win it all, too.

Mr. McClusky is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit baseballprospectus.com.