The world’s oldest knockout competition enters its 154th season with the same question every February: can anyone stop the big six? Since the FA Cup seeded the fifth-round draw in 2016, only one team outside the Premier League’s top six has reached the final. Yet the romance of the Cup survives in the margins—on muddy pitches, in 90th-minute scrambles, and in the spreadsheets of quants who now model its chaos better than ever.
Expected Goals (xG) models built on 12 years of Cup data show a stark pattern: when a Premier League side resting 4+ starters still posts an xG difference of +1.3 or greater, they advance 87 % of the time. Leicester’s 2021 quarter-final win over Manchester United was the single anomaly in 42 such fixtures. That same model flags three matches in the 2025 fifth round as “giant-killing alerts”:
1. Coventry City v Newcastle – Coventry’s high press has created 0.37 xG per forced high turnover, third-best in the Championship. Newcastle’s rotated back-four averages 0.41 xGA when Sean Longstaff is rested, a 29 % increase. Upset probability: 31 %.
2. Southampton v Liverpool – Southampton’s 3-4-3 under Russell Martin concedes only 0.89 non-penalty xGA at St Mary’s since December. Liverpool’s front five rotation policy drops their away xG by 0.6 when Salah starts on the bench. Upset probability: 27 %.
3. Ipswich Town v Chelsea – Ipswich’s set-piece machine (14 goals from corners, most in the EFL) meets Chelsea’s zonal system that concedes 0.21 xG/90 from dead balls under Pochettino. Upset probability: 22 %.
Beyond the spreadsheets, travel distance remains the last truly random variable. Teams travelling >150 miles mid-week suffer a 0.15 xG swing in the first 30 minutes, equal to one half of a goal. That edge explains why Nottingham Forest’s fourth-round replay win at Bristol City looked inevitable to the models once Forest bussed straight from their Marbella retreat, cutting journey fatigue by 18 %.
The winner? Manchester City. Their second-string still grades out to 1.94 xG/90, and with the draw opening up on the same side as Everton-West Ham victor, the Opta simulator makes City 34 % likely to lift the trophy—higher than any team since peak Guardiola in 2019. The magic is real, but the math is louder.
