Expected Assists

Expected Goal Chains: The Link between Passing Sequences and Shots by Kevin Shank

For those who are not familiar with Expected Goal Chains (xGC), the metric looks at all passing sequences that lead to a shot and credits each player involved with the xG. Instead of just looking at expected goals and expected assists, which primarily benefits strikers and attacking midfielders, xG Chains is beneficial to every player involved in a sequence. Most importantly xGC credits those defensive or two-way players who are integral to a play’s build-up but don’t necessarily serve that final key pass. To calculate xGC, I assembled every pass, shot, foul, and defensive action so far in MLS and assigned a unique ID to each passing sequence. When a sequence ended in a shot, each player is attributed with the xG from that shot. StatsBomb defines it very succinctly, so the below steps are stolen directly from them: 

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