For all intents and purposes, the Mariners look to be the real deal this year. Their pitching staff is strong, providing 8.7 WAR, the 6th-best mark in the majors. The offense has been equally impressive. Their 108 wRC+ ranks 4th in the MLB. They have the third most wins in baseball (46) and sit just 1.5 games back of the defending champion Houston Astros for first place in the Al West. Yet for every positive attribute that this year’s squad seems to boast, there is one glaringly obvious problem: their run differential.
Seattle’s run differential is +22, 12th best in baseball. It’s nothing to turn your nose up at, but it’s far lower than their competitors. The three teams ahead of them in the American League, the Red Sox, Yankees, and Astros, have run differentials of +108, +98, and +157, respectively. They more closely resemble the 37-33 Cleveland Indians (+28) than they do the 42-29 Braves (+67). They’re even outpacing the rival Angels by 8 games in the standings despite a worse differential.
So why does run differential matter?
It’s all fine and dandy to win a game or two by one run. The 2017 World Series Champion Astros won 19 such games over the course of the season. The Mariners, however, have already won 23. Let’s just say it’s not a recipe for success. The 2016 Rangers are a prime example. Over the course of the season, they amassed an astounding 36-11 record in one-run games. They finished with a record of 95-67, 13 wins better than their expected record of 82-80. But the magic ran out when they were swept by the Blue Jays in the ALDS.
How crazy is this Mariners' season? With their 46-25 start, half their wins have been by one run (23-10). Since 1908, no other team has had 23 one-run wins in the first 71 games of a season. The 1938 Pirates had 22.
— Greg Johns (@GregJohnsMLB) June 17, 2018
The record for the most one-run wins in a single season belongs to the 1978 Giants, who won 42 such contests.
The Mariners are on pace to win 52 games by one run.
That’s really cool, but it’s also extremely alarming. Baseball is a sport that revolves around sustainability, and unfortunately, one-run wins are not. There’s a fine line between being able to win close games and relying on winning them. In the past ten years, only one team has won the World Series while winning 30 or more one run contests. The 2012 Giants. They finished with exactly 30.
It’s easy for us to get excited for the Mariners. They haven’t made the playoffs in 16 years. And it’s fun to watch a seemingly cursed team thrive in the face of adversity. But cautious optimism is the name of the game. What happens when Cano comes back from his 80 game suspension? What happens if they make the playoffs and have to play without the aforementioned Cano?
And what happens if the one-run magic runs out?