With two different 10-game winning streaks this season, the Astros have a firm hold on the American League West, entering Wednesday leading the division by 8 1/2 games with the Rangers, A's, Angels and Mariners all in a similar position and within 2 1/2 games of each other.

The Astros were the heavy favorites to win their third consecutive division title and that hasn’t changed with their dominant showing so far. The Angels and A’s were expected to compete for an AL Wild Card spot and still have hopes of making the postseason, while the Rangers have surprisingly held their own despite some key injuries and the Mariners have struggled since their hot start.

There are plenty of numbers to explain each team’s position in the standings so far, but here’s a look at one key number for each team in the AL West this season:

A’s: 10
The bullpen was expected to be a strength for the A’s this season, but they lead the Majors with 10 blown saves. It comes on the heels of Oakland making the postseason last year with one of the most dominant bullpens in baseball.

It's not exactly the same cast this year, but closer Blake Treinen and setup man Lou Trivino returned but haven’t been quite as effective. On the season, A’s relievers have combined to post a 4.09 ERA that ranks in the middle of the pack, which isn’t at the same level as last year when the bullpen’s 3.37 ERA was the third-best mark in baseball. The bullpen will need to turn it around if the A’s have any chance of returning to the playoffs, as the Astros have already started to run away with the division.

Angels: 213 1/3
The Angels have leaned heavily on their bullpen so far this season with their relievers combining to lead the Majors with 213 1/3 innings pitched. It’s been part of their strategy to limit their starters’ exposure to a third time through the lineup, but there are concerns it could wear down the bullpen as the season goes along.

Angels starters have combined for a 5.64 ERA that’s the second-worst mark in the Majors behind the White Sox while also throwing the second-fewest innings. Some of that is skewed because they’ve used an opener seven times this year, but it’s clear the Angels are searching for answers on the pitching side, and it’s a reason why they’ve struggled to reach .500 this season.

Astros: .505
The Astros have been knocking the cover off the ball this season, as their .505 slugging percentage leads the Majors and if they keep it up at this current pace it would be the highest ever by a club in a season. The Red Sox hold the record with a .491 slugging percentage in 2003.

George Springer (.654 slugging percentage), Carlos Correa (.567), Michael Brantley (.561) and Alex Bregman (.554) lead the way, and all rank among the top 12 in the AL. Springer’s slugging percentage is second in the AL to the Rangers’ Joey Gallo, who leads with a .687 mark. The offense is expected to continue to be a strength for Houston, which also boasts an impressive pitching staff that has combined to register the second-best ERA in the Majors.

Mariners: 45
The number of players used already by the Mariners this season as they’ve churned through the most roster turnover of any team in the Majors, including an MLB-high 29 pitchers. General manager Jerry Dipoto is always active and he’s on a frenetic pace this season, in part because the club’s rebuilt bullpen has been in constant search for help. The 45 players used already is second most in franchise history for a season and there’s four more months and the Trade Deadline still to go.

The club has used 23 different relievers, with four more newcomers added just this past week. Of Seattle’s original eight-man bullpen, only three still remain on the 25-man roster just two months into the season. That turnover is indicative of Seattle’s season, which started out with a 13-2 record before flipping to the worst record in MLB over the next 35 games. And Dipoto figures to have more moves coming as he looks to deal short-term veterans like Edwin Encarnacion, Jay Bruce and others for future help.

Rangers: .311
That's the combined batting average for Danny Santana, Hunter Pence and Logan Forsythe, who were all signed to Minor League contracts this offseason. They each played well enough during Spring Training to make the club, and the three veterans have been surprising sources of production so far, as they’re all hitting over .300 and all have a slugging percentage north of .500.

They are also quite versatile as they’ve combined to start at seven different positions. Offensively, they’ve have also combined for 17 home runs and 66 RBIs in 331 at-bats. Their versatility has been essential because the Rangers have been going with eight relievers all season, which gives them just a three-man bench. It’s given the Rangers much more depth than they’ve had in recent years, and it’s keeping the team afloat as they’ve dealt with injuries to key players such as first baseman Ronald Guzman, second baseman Rougned Odor and shortstop Elvis Andrus.