Byron Black defeated Marcelo Rios 7-6 3-6 6-2 7-6 in the ZIM vs CHI round robin on hard. The upset overturned the form book — Marcelo Rios came in leading the head-to-head 5–2. Byron Black narrowed the head-to-head to 5–3.
Black B. came through in four sets.
Black B. and Rios M. faced 3 of the same opponents in the last 12 months. Black B. went 2–1 (67%) against them, Rios M. 2–1 (67%). Results against comparable opponents are close (1 : 1 better-results split).
Only 3 common opponents — small sample, treat as indicative.
Hard: level 3–3 · Clay: Rios M. leads 2–0
Byron Black beat Marcelo Rios 7-6 3-6 6-2 7-6. Umpiry, "Byron Black vs Marcelo Rios — ZIM vs CHI Round Robin", https://umpiry.com/match/1999-09-24/black-vs-rios-zim-vs-chi-rr?utm_source=cite (as of 24 September 1999).