We see it in their dugouts and postgame celebrations. No two teams are having more fun than the Mariners and Astros right now. We admit we didn't think the American League West race would be this good.
To put it bluntly, we didn't think the Mariners were good enough to hang with the Astros. And yet here we are with both teams on pace to win 100 games and possibly fight for a division championship.
The Astros lead the Mariners by 1 1/2 games despite finishing a 10-0 road trip on Sunday with a 7-4 victory in Kansas City. They've won 11 in a row overall and will try to tie the Houston franchise record of 12 straight wins on Monday night at Minute Maid Park against the Rays.
Meanwhile, the Mariners have been crazy good for more than a month -- 22-7 since May 18 after Sunday's 9-3 loss to the Red Sox at Safeco Field. They're winning one-run games at a historic pace -- 13 of 16 and 23-10 overall. Their bullpen has been spectacularly good.

Here's the thing about a team like the Mariners, a team that began the season with a touch of uncertainty concerning how good it was after a disappointing 78-84 record in 2017.
As they've kept winning and seamlessly absorbed the loss of their best player, Robinson Cano, to suspension, their confidence has soared. These are dangerous teams for the rest of baseball.
It's logical to argue that winning a historically high percentage of one-run games isn't sustainable, and history says it's not. But if you're the team winning those games, you say they're a tribute to grit and determination and resilience. That's what the Rangers said in 2016 when they were 36-11 in one-run games, and like the Orioles (29-9) in '12.
The Astros and Mariners don't play each other until July 30 when they go at it seven times in a two-week period. Until then, they can continue to shadow one another from afar.
So in picking the best game each day this week, the AL West leaders will be getting the nod:
Monday: Rays at Astros (8:10 p.m. ET, MLB.TV)
The Astros return to Minute Maid Park for a nine-game homestand against the Rays, Royals and Blue Jays after the best road trip in franchise history. They're 10 for 10 since beginning a stretch of 36 straight games against teams below .500.
Tuesday: Mariners at Yankees (7:05 p.m. ET, MLB.TV)
For the Mariners, this is the start of a three-city, 10-game road trip to play the Yankees, Red Sox and Orioles. The Mariners have lost back-to-back games once since May 18 and have had four walk-off celebrations. Meanwhile, the Yankees have won 13 of 17 and are in a virtual tie with the Red Sox in the AL East.

Wednesday: Dodgers at Cubs (2:20 p.m. ET, MLB Network, MLB.TV)
This is a matchup of two teams that appear headed for the postseason after slow starts. The Dodgers have overcome a laundry list of injuries and a 16-26 start to win 21 of 28 overall and 11 of 14 this month. Super utility man Player Page for Max Muncy has been one of the most pleasant surprises of the season. As for the Cubs, they've rushed back into the mix in the National League Central after falling 4 1/2 out in late May.
Thursday: Cardinals at Brewers (8:10 p.m. ET, MLB.TV)
This suddenly is an important series for the Cardinals, who've had a tough week and are trying to keep the Brewers and Cubs within shouting distance in the NL Central. Meanwhile, the Brewers have lost eight of 14 this month.

Friday: Mariners at Red Sox (7:10 p.m. ET, MLB.TV)
The Mariners attempt to keep the magic going against a team that has been atop the AL East for 62 games and appears to have few weaknesses. If there's any suspense around the Red Sox, it might be whether J.D. Martinez or Mookie Betts will get closer to Michael Trout in the AL MVP balloting.
Saturday: Padres at Giants (4:05 p.m. ET, MLB.TV)
The Giants believed getting Madison Bumgarner back might be the spark they needed. That might be the case at some point, but with Evan Longoria, Johnny Cueto and Jeff Samardzija on the disabled list, they've fallen behind the D-backs, Dodgers and Rockies in the NL West.
Sunday: Phillies at Nationals (8:05 p.m. ET, ESPN)
The Nationals remain solid favorites to win the NL East, but injuries have kept them from overtaking the Braves. The Phillies have won five of seven since a 1-7 slide.