Every year, there's a team that finished under .500 the year before that makes the playoffs. You may not classify all these teams as surprise teams but all certainly made significant improvement from the season before. Witness:

--2014 Giants: 76 wins to 88 wins (and a World Series title)

--2014 Angels: 78 wins to 98 wins

--2013 Red Sox: 69 wins to 97 wins (and a World Series title)

--2013 Pirates: 79 wins to 94 wins

--2013 Indians: 68 wins to 92 wins

--2012 Nationals: 80 wins to 98 wins

--2012 Reds: 79 wins to 97 wins

--2012 A's: 74 wins to 94 wins

--2012 Orioles: 69 wins to 93 wins

--2011 Brewers: 77 wins to 96 wins

--2010 Reds: 78 wins to 91 wins

--2009 Rockies: 74 wins to 92 wins

--2008 Rays: 66 wins to 97 wins (and a World Series berth)

--2008 White Sox: 72 wins to 89 wins

--2007 Indians: 78 wins to 96 wins

--2007 Cubs: 66 wins to 85 wins

--2006 Tigers: 71 wins to 95 wins (and a World Series berth)

Evan Gattis hit 22 homers in just 369 at-bats last season for the Braves. Geoff Burke/USA TODAY Sports

That's at least one surprise team each of the past nine seasons and nine over the past three. It appears the sport has changed in recent years, with increased parity making these types of leaps more likely. It seems probable we'll see at least another couple of teams make the jump from sub-.500 into the playoffs in 2015.

The Red Sox (71-91 a year ago) and the Cubs (73-89) are popular choices to do this following their big offseason deals. But I'm throwing out the Houston Astros as a potential surprise team. They went 70-92 last year -- following three straight 100-loss seasons -- and were outscored by 94 runs, so they certainly aren't the 2014 Giants or 2013 Red Sox, clubs with recent success on their résumés.

General manager Jeff Luhnow just made two more moves this week to continue his overhaul of a lineup that finished next-to-last in the American League in runs scored, trading center fielder Dexter Fowler to the Cubs for third baseman Luis Valbuena and pitcher Dan Straily and then signing free-agent outfielder Colby Rasmus. This after acquiring Evan Gattis and signing shortstop Jed Lowrie.

As Buster Olney wrote Wednesday morning, it's a risky approach with so many strikeout-prone hitters:

Two-hundred-sixty-three hitters had at least 300 plate appearances in 2014, and five of the hitters who appear poised to start in Houston's lineup finished in the top 19 in the majors for highest strikeout percentage. Here's a look at their possible lineup, with last season's K percentage and ranking: 2B Jose Altuve, 7.5 percent (262nd highest among 273 hitters) 3B Luis Valbuena, 20.7 percent (93rd) SS Jed Lowrie, 14.0 percent (219th) DH Chris Carter, 31.8 percent (14th) RF George Springer, 33.0 percent (7th) CF Colby Rasmus, 33.0 percent (9th) LF Evan Gattis, 23.2 percent (53rd) 1B Jon Singleton, 37.0 percent (1st ) C Jason Castro, 29.5 percent (19th) The Astros will be the latest team to test the theory that all outs are created equal, that an out is an out, and it really doesn't matter whether you slap a ground ball to second base or strike out.

Buster then included a list showing that in recent seasons the most prolific strikeout teams have rarely ranked high in runs scored. But here's what Luhnow is thinking and why the Astros' offense should still be much improved over 2014 (I also ran these numbers the other day after the Gattis trade):

--Astros first basemen in 2014: .168/.277/.307 (30th in wOBA)

--Astros third basemen in 2014: .212/.255/.321 (30th in wOBA)

--Astros left fielders in 2014: .218/.286/.318 (30th in wOBA)

(Astros shortstops actually ranked 10th in the majors with a .302 wOBA and Lowrie's wOBA in 2014 was .299, so he may be an upgrade over Jonathan Villar only if he hits like he did in 2013, when he posted a .342 wOBA.)

Anyway, the Astros had the worst offensive production in the majors at three positions. They've acquired players to play those positions and give new manager A.J. Hinch all kinds of flexibility; if Singleton doesn't hit, for example, Carter can play first base, Gattis DHs and one of the young outfielders plays left. Which, given Gattis' defense, is maybe the most likely scenario. They brought in Hank Conger, an excellent pitch-framer, for catching depth. Springer could develop into a big star.

I do agree with Buster: The strikeouts are a huge issue and maybe the offense craters like the Braves did last season. But with even minimal improvement at first base, third base and left field, plus improvement and a full season from Springer, the Astros could score close to 729 runs instead of 629 -- and the A's ranked third in the AL in 2014 with 729 runs.

But there's another reason the Astros will improve. They were just 57-11 when leading entering the eighth inning and 61-8 when leading entering the ninth, as the bullpen had the worst ERA in the majors. The average team lost 5.9 games when leading after seven and 3.3 when leading after eight. New relievers Luke Gregerson and Pat Neshek should help here even if they're just OK.

The rotation isn't highly regarded but had the same ERA as Cleveland's and everyone is raving about Cleveland's rotation. The Astros had a 3.82 rotation ERA; the Giants, playing in the NL and in a great pitcher's park, had a 3.74 ERA. The Astros had a better ERA than the Tigers' rotation. Yes, Dallas Keuchel and Collin McHugh have to prove they're the real deal and the back of the rotation has to sort itself out, but there's some potential depth now with Straily, Alex White, Asher Wojciechowski and prospect Mark Appel on the way to fight for jobs.

Look, more than likely 2015 will be a bridge year. The AL West is going to be tough with the Angels, A's, Mariners and a possible rebound season from the Rangers. But the Astros had glaring weaknesses last year and Luhnow has addressed those weaknesses. He's been collecting talent for three years and now the Astros have surprise team written all over them.