The Seattle Mariners have ended their losing streak at 17 games, with a 9-2 win today over the New York Yankees.

Frank Vaccaro, one of the streak experts in the Society for American Baseball Research (SABR), recently informed members what the longest baseball losing streaks of all time are. Restricting the list to 1900 and beyond, the longest losing streak was 23 by the Philadelphia Phillies in 1961. The 1988 Baltimore Orioles lost 21 straight, with the added twist that the losses were to start off the season (i.e., the O's had an 0-21 record at one point).

With their skid now concluded at 17 games, the 2011 Mariners officially have ended up tied for 23rd place in the all-time rankings for longest major-league baseball losing streaks (tied for 14th if one excludes teams from before 1900).

UPDATE: Jesse Wolfersberger at Fan Graphs estimates the probability of the Mariners' 17-game losing streak, using betting odds to derive the game-specific win probabilities. After the game-specific projections are converted to loss probabilities (1 - Win Prob), they are then multiplied together. A lot of commenters chime in on Wolfersberger's analysis, too.

The Seattle Mariners have now lost 14 games in a row, the longest losing streak this year in Major League Baseball. According to ESPN Stats & Information, the longest skid in the past 15 years is 19 games, by the 2005 Kansas City Royals. Before going on the 14-game losing streak, Seattle was actually a .500 team (43-43). However, the Mariners have lately been facing some of the better teams in the American League, such as the Angels, Rangers, and Red Sox (see game-by-game log). Seattle has one game remaining at Boston in the teams' current series, and then a three-game stand at Yankee Stadium, so an end to the losing streak may not be imminent!

With baseball's Texas Rangers on a winning streak that reached nine games last night (including shutouts in the last three contests), Gary Collard sent a message to the Society for American Baseball Research (SABR) listserve discussion group, noting the weak opposition faced by Texas in recent weeks:

"The Rangers ended the pre-All Star break portion of their schedule by playing 16 of 19 games against last place teams. I think this is probably a record, since you would pretty much have to have two interleague series against your 'designated rival' to hope to match it (6 divisions is likely a must as well)."

The reference to a designated rival, in this case, describes the Rangers' six games against the Houston Astros (last place in the National League Central) on June 20-22 and 28-30, as a special geographic match-up during interleague play. Other last-place teams played by Texas include Florida (NL East, July 1-3), Baltimore (American League East; July 4-6), and Oakland (AL West, July 7-10). Also, the Seattle Mariners, against whom the Rangers have won the first two games of a current four-game series, are only slightly better than last in the AL West. The Rangers' last loss came in the finale of the Florida series.

Tom Ruane followed Collard's SABR message with one of his own. Because divisional play didn't begin until 1969 (prior to that, there only would have been two last place teams at a given time, one each in the AL and NL), Ruane used a different approach, focusing on opponents with poor records. One of Ruane's findings was that four times since 1900 has a team played 19 straight games against teams with winning percentages below .400. The most recent such team was the San Francisco Giants, who did so from May 21 to June 10, 2004, going 13-6.

My curiosity piqued, I decided to look up the Giants' streak myself. During the stretch, San Francisco played two games against the then-Montreal Expos (whose winning percentage was around .333 at the time); seven against the Arizona Diamondbacks (who peaked around .38 during these games); seven against the Colorado Rockies (who peaked around .39); and three against the Tampa Bay Rays (around .39).

Last January, I found a basketball analogue to the current Texas Rangers' situation, namely how a 19-out-of-20 winning stretch by the Miami Heat involved very few games against the NBA's best teams.

U.S. women's soccer goalie Hope Solo had her streak of 796 minutes without allowing a goal end today, in the Americans' 2-1 loss to Sweden in the women's World Cup (90 minutes is the regulation game length). The streak-ending goal came on a penalty kick, which is a special type of play that is especially difficult for the goalie to defend. However, Sweden scored again roughly 20 minutes later, so Solo's streak would have ended in the same game (albeit a little further along), even if we exclude penalty kicks.