The 2015 season is thus far going swimmingly for the Tigers and Royals, who, after a pair of series sweeps, are each 6-0 and, not coincidentally, easily boast the top two run differentials in baseball. We’re of course but toe-deep into 2015, but these are notable starts, particularly for teams that figure to be genuinely relevant over the longer haul to come (we're talking about two playoff teams from a season ago).

Since 1914 (the back end of searchable data), 43 teams -- not counting the 2015 Tigers and Royals -- have started the season 6-0. Here’s how those 43 winning streaks played out …

  • Eighteen teams saw their win streaks end at six.

  • Ten teams saw their streaks end at seven.

  • Three teams pushed their win streaks to eight.

  • Six teams won nine in a row to start the year.

  • Three teams won 10 in a row to begin, and one team won 11.

  • Two teams -- the 1982 Braves and 1987 Brewers -- won a record 13 in row at the start of the season.

Obviously, it remains to be seen how long the current Tigers and Royals models keep their streaks going, but already, with six in a row to start the year, they’re in somewhat rarefied air (again, just 43 teams in the last 100 years or so). So what does such a hot start augur for the future?

Those 43 teams to start the season 6-0 (or better) have combined for a winning percentage of .565. Scaled to a 162-game season and rounding off, that comes to a mark of 92-70. Of those 43 teams, just four -- the 1968 Twins, 1985 Mariners, 1987 Astros and 1992 Yankees -- finished with a losing record. On the positive end of things, 18 of the 43 teams in question -- or 41.9 percent -- made the postseason. Of those 18 playoff teams, nine went on to win the World Series (the 1984 Tigers among them).

If that playoff percentage of 41.9 -- i.e., the percentage of teams starting the season 6-0 that went on to make the postseason -- strikes you as a bit low, let’s keep in mind that the healthy majority of our sample played when the playoff field was much smaller than it is now. Specifically, 20 of 43 played before the era of divisional play, and another 13 played before the wild card was instituted (this figure doesn’t include teams from strike-shortened 1981, when the playoff field was expanded for just that one weird season).

The takeaway is that, the Royals and Tigers, with two wild cards in each league in play, may perhaps be even better positioned to make the playoff fray than the vast majority of those other teams that got off to 6-0 starts. Put another way, the Royals and Tigers from this point forward could play .500 ball and still finish with 84-78 records. In this era of increasing compression in the standings, that may be enough to fetch a second wild card berth. Of course, KC and Detroit are likely better than that.

In terms of playoff odds and the hot starts of these two teams, let's turn to the FanGraphs numbers. Using FanGraphs' season-to-date mode, the Tigers and Royals, we find, opened the 2015 season with, respectively, a 41.6 percent and 39.8 percent chance of making the postseason. After those 6-0 starts, the Tigers and Royals check in with, respectively, 65.2 percent and 63.4 percent chance of making it. Yes, the season-to-date numbers are subject to wild swings in the early going, but that's still a substantial leap in any context. 

To be sure, there’s a selection bias going on, as certifiably good teams are more likely to start the season 6-0 than are bad or middling teams. That said, the Tigers and Royals have put themselves in generally enviable company by virtue of their perfect starts to the season.

Oh, and for those wondering, the two AL Central rivals of note don't meet for the first time in 2015 until April 30 in Kansas City. Developing!

(Wink of the CBS eye to the wonderful and necessary Baseball-Reference Play Index)

So far, so good for Ned Yost (left) and Brad Ausmus. (USATSI)
So far, so good for Ned Yost (left) and Brad Ausmus. (USATSI)