Early season baseball results are often funky.

There are players high on the leaderboards of certain statistical categories that have no business being there and, before too long, probably won't be. There are teams (like the Washington Nationals) that are struggling that most people think will turn things around and end up doing well. And there are teams who jump out to a fast start and end up faltering as the season wears on.

This begs the question: are the Houston Astros for real? After Sunday's 7-6 win over the Seattle Mariners in Houston, it's fair to wonder.

Yes, that's right, the team that has not had a winning season since 2008 and had averaged 104 losses a season over the last four seasons, has won 10 straight games and sits atop the AL West standings with the best record in the American League.

Their 18-7 start is the best in team history, and during their 10-game winning streak they've outscored opponents 76-37. Their plus-37 run differential is third-best in baseball, behind only the Kansas City Royals (plus-45) and the St. Louis Cardinals (plus-40), and their 10-game winning streak is the longest since a 12-game stretch back in August-September of 2004.

There are several reasons why the Astros are playing so well and why this may not be a mirage. Simply put, they've been working on this for a long, long time. Here's how they're doing it.

Power

The #Astros lead MLB with 40 home runs. #Power pic.twitter.com/9jMI7H4Ytm

— #VoteAstros (@astros) May 3, 2015

Coming into the season, everyone knew Houston was going to hit a lot of home runs. We also knew they were going to strike out a lot. And while so far, both have been true, the home runs have been far more beneficial than the strikeouts have been debilitating.

After crushing two home runs on Sunday, designated hitter Evan Gattis is now tied for the team lead with new third baseman Luis Valbuena (acquired from the Cubs over the winter) with six. Free agent outfielder Colby Rasmus has five, and Jed Lowrie and George Springer each have four. Eleven different Astros players have gone deep so far in 2015, which just shows how deep their wellspring of power goes.

Patience and Speed

In addition to their power, Houston has also done it with patience at the plate and speed on the bases.

They lead the AL in stolen bases with 31, seven more than the next-closest team. And they are second in the American League in walks taken. So even though their batting average and on-base percentage are middle-of-the-pack in the American League, their ability to hit homers, work walks, and steal bases has enabled them to score 125 runs, fourth-most in the AL.

Jose Altuve is having another outstanding offensive season, hitting .361/.407/.509 in 108 at-bats this season. But the surprise player so far this season is center fielder Jake Marisnick, who leads the team with a .382 average, a .427 on-base percentage (OBP) and 1.059 OPS in 68 at-bats. Both players have nine stolen bases each, leading the team.

They Have An Ace

Dallas Keuchel emerged last year as one of the nastiest left-handed starters in all of baseball, with a 2.93 ERA in 200 innings. In five starts this year (37 innings) he's given up just three earned runs total, for an ERA of 0.73.

This is despite the fact that Keuchel is not a strikeout pitcher. He's only averaged 6.22 strikeouts per nine innings throughout his four-year MLB career, and so far this year it's only 5.35. He has been helped by a .157 batting average on balls in play (BABIP) and an 88.9% left on base percentage this season, and those numbers will obviously correct themselves over time. But even if they do, his Fielding Independent Pitching of 2.84 indicates he'd still be one of the AL's best starters.

The rest of the starting rotation has been good-to-decent. Collin McHugh has followed up a solid 2014 season with a good first month as well, posting a 3.41 ERA in his first five starts. In all, Houston's starting pitchers have posted a 3.64 ERA as a team, behind only Oakland and Tampa Bay in the American League.

Bullpen Bullies

Here is one of the more fascinating stats of the 2015 season so far.

If you fall behind the Astros, you might as well give up Astros made it 18-0 today in games they've led pic.twitter.com/sloJ0dHu1Y

— ESPN Stats & Info (@ESPNStatsInfo) May 3, 2015

In other words, if you want to beat Houston, score early.

Much of this is due to the outstanding work of the bullpen, which has a 2.13 ERA so far this year, third-best in the American League. Their 86 strikeouts are fourth-most, but what is most impressive is how stingy they've been with issuing free passes, just 17 so far, fewest in the league. They are second in the AL with 9.43 strikeouts per nine innings and own a league-best 1.86 walks per nine innings.

That's a darn good combination of stats for a bullpen, and is a huge improvement over a 'pen that had a 4.80 ERA last year -- far and away the worst in the AL. It gave up the most home runs in the league (55), blew the most saves (25), had the fewest number of saves (31), and gave up the most earned runs (250). By a lot.

Closer Luke Gregerson has been outstanding this year, with six saves and a 2.77 ERA in 13 innings. Will Harris has yet to give up a run in 13 innings, and Tony Sipp, Chad Qualls, and Pat Neshek all off to fine starts as well.

This is better.

Solid Defense

Houston has also played good defense by most metrics so far this year.

According to Fangraphs, Houston has had the third-best defense so far in the American League, with six Defensive Runs Saved (DRS). They've made just 11 errors, third-fewest in the AL and have a .989 fielding percentage that is tied for second-best in the league.

Will It Continue?

The Astros have been building toward contention for a few years now, with some upset at the team's apparent "tanking" in an effort to secure as high a draft pick as possible for a number of years. And while the team failed miserably in that regard this year with the Brady Aiken un-signing, they do have a stud in 2012 top pick Carlos Correa on the horizon and hold out hope that 2013's top pick Brady Aiken can bounce back after a rough season last year.

Over the winter, general manager Jeff Luhnow said his team was ready to be a winning team again, but even he couldn't have imagined they'd have gotten off to this hot of a start.

I still think the team needs another top pitcher in order to truly contend in a division that doesn't figure to stay this mediocre all season long. Either the Angels, A's, or Mariners are going to get hot and get back into the race, and when they do, the Astros would be well served to have another number-one arm at their disposal.

That being said, if the offense continues to pound the ball over the fence and the bullpen can hold up, there's no reason to think Houston can't hang around and actually make the postseason for the first time since losing the World Series in 2005.