ERA

Earned Run Average — the number of earned runs a pitcher allows per nine innings. Lower is better; a starter under ~3.50 is strong. Recent-form ERA (last 5 starts) shows whether a pitcher is hot or slumping versus his season line.

• WHIP — Walks + hits allowed per inning. Under ~1.10 is excellent, over ~1.40 is shaky.
• K/9 — Strikeouts per 9 innings — swing-and-miss rate. ~9+ is high-strikeout.