Week 21 of 2025 in fantasy baseball tightens the waiver-wire playbook across five categories, with three under-the-radar options per category highlighted. rostered thresholds cap at 50 percent on Yahoo, encouraging strategic streaming for runs, homers, RBIs, steals and AVG as the stretch run begins. Frelick, Simpson and Varsho anchor Runs; Andujar, Sosa and Colby Thomas bring home-run upside; Steer, Gurriel Jr. and Rice offer RBI punch; Crews, Caballero and Freeman supply speed; Collins, Marte and Ortiz push batting-average help to shored up lineups.

These names are positioned to deliver immediate contributors in the coming weeks, with multi-eligibility and favorable batting-order spots cited as meaningful leverage. Managers should balance at-bats with rostership and park factors, leveraging recent two-week bursts and weekly trends to maximize category boosts as playoff races heat up.