What can history tell us about teams coming home for 2nd legs?

Coming into the second legs of their playoff series, the four home teams will feel varying degrees of confidence about their chances to advance to their respective Conference Championships. Looking at MLS Cup Playoffs results since 2007, we can see how certain these teams actually should be.

Since 2007, there have been 26 two-legged playoff series in MLS, all of which can be used to see what the outcomes might look like on Wednesday and Thursday.

Real Salt Lake and Sporting Kansas City will both come into their games this week down one goal after losing over the weekend on the road. Both of these teams should feel that losing by only one goal in a road playoff game is not too big a challenge to overcome.

But consider this warning: In the 26 playoff series since 2007, eight teams have come into their home second leg down exactly one goal. Only two of these teams have been able to advance to the next round of the playoffs -- the 2007 Houston Dynamo (which had to rely on extra time and a red card to beat FC Dallas) and the 2009 Chicago Fire, against New England.

New York come into their home game tied against Houston after losing their lead in stoppage time. Eight teams have come into their second leg home game tied with their opponents, and five have been able to advance. That's a 62.5 percent winning percentage -- roughly in line with the Red Bulls' 2013 regular season 65 percent home record.

After beating Seattle on the road in the first leg, Portland will be flying high heading into the friendly confines of JELD-WEN Field. History, though, says it's far from a sure thing: Five teams have had second-leg home matches after after a one-goal win since 2007, and just three have been able to advance to the next round. That's 60 percent.

We only need to look back to last year for this exact scenario. San Jose led LA 1-0 going into their home leg, but their Supporters' Shield-winning season was promptly ended when the Galaxy scored three goals in the first 39 minutes.

The other time a team came home for the second leg up a goal and lost also involved the Earthquakes, back in 2010. They lost the Buck Shaw opener to the Red Bulls, but then reversed it with a 3-1 win in Red Bull Arena to advance to the Eastern Conference Championship.

Looking at league history can give us a glimpse into what we should expect in these second legs. However, with the MLS Cup Playoffs, we know to always expect the unexpected.

Stay connected: The official MLS app keeps you connected with the latest news, highlights, scores, standings, and analysis all for FREE. Download for iOS (Apple) or Download for Android