Retroactive Reprocesses all prior tournaments each time new data arrives, using full-season context to set initial rating. Early wins against players who later prove strong are valued accordingly. Leads to the value of wins changing retroactively over time. Recommended for end-of-season reference.

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Sequential Processes tournaments in order, using only information available at the time (though some effort is made to give 'new' players a rough initial rating). Each tournament's ratings are final once committed. More conservative — a win is only worth what the opponent was rated at that moment. More traditional means of ranking.