Reason for optimism: Seattle discovered the joys of offense last season, and this offseason, the Mariners added a guy who outslugged Paul Goldschmidt last season.
Reason for pessimism: The addition comes at the cost of up to 30 starts from Yovani Gallardo.
The Mariners increased their run production by 112 runs from 2015 to 2016, and close to half of that increase came from the easiest source of improvement a team will likely ever have. By replacing their 2015 catchers, who collectively hit worse than at least one National League pitching staff in 2015, with nearly exactly league-average catcher production, the Mariners gained roughly 50 runs last season.
The other 70 runs of marginal improvement partially came from yet another career year from Kyle Seager, who has seen his home runs increase every season since his debut in 2011, and a spectacular year from Robinson Cano, who hit more home runs last year (39) than he did in his first two seasons with Seattle (35).
