Historically, four basic statistics correlate most strongly to Cy Young winners: Wins, ERA, strikeouts and WHIP (walks and hits per inning pitched).
However, there has been a clear upwards trend in recent seasons regarding WAR and Cy Young winners — which mirrors the trend between WAR and MVPs.
Until 2003, the Cy Young winner finished at least 1 WAR behind the pitching WAR leader (for that league)'48% of the time. Since 2004, that difference has only occurred six times (19%), a decrease of 29%.
Twelve of the past 14 Cy Young winners have finished in the top three in their respective leagues in pitching WAR — the only exceptions being Blake Snell (2018) and Robbie Ray (2021).