Bookmakers price the over 4.5 goals line at 50 % and the under at 59 %. Charlton average 1.4 goals per game, Chelsea 2.4. Given the gulf in quality and Chelsea’s attacking output, the probability of over 4.5 goals is assessed at 48 %.
Odds imply a 96 % chance for Chelsea, 6 % for a draw and 3 % for Charlton. Historical results (4:0 and 0:4) and current form support a 95 % probability of a Chelsea win, 4 % for a draw and 1 % for Charlton.