Bronson Arroyo barely made my Top 50 free agents, which meant I saw him as a candidate for a low-dollar, one-year deal, not the substantial two-year deal Arizona just gave him in spite of all of the red flags in his recent history.
Arroyo does two things well: Stay healthy and throw strikes. Those are valuable skills, although one's ability to stay healthy declines with age, and Arroyo just signed for his age-37 and 38 seasons. They're also increasingly overshadowed by the things Arroyo doesn't do well: throw hard, keep the ball in the park or get left-handed hitters out.
Arroyo's fastball averaged just barely higher than 87 mph over the last three seasons, according to Fangraphs, more than 2 mph below his peak years. While some of that is a function of him attempting to throw a sinker, the pitch doesn't have great sinker movement, and he's not a ground ball pitcher. What often happens is Arroyo throws a below-average pitch without much life somewhere in the zone, which a good major-league hitter would politely refer to as a “BP fastball.”