Why PCT, not points?
Test series vary in length — Australia vs England play 5 Tests (the Ashes), while West Indies vs Bangladesh might play 2. If you ranked teams by raw points, hosting longer series would inflate totals unfairly.
PCT (Percentage of Points Available) solves it: divide the points you won by the maximum you could have won. A team that wins 4 of 6 Tests has the same PCT (66.7%) whether those Tests were against South Africa or Sri Lanka.
The Final
The two highest-PCT teams meet in a single Test at a neutral venue (Lord's in 2027). A reserve day is built in to deal with rain. A draw or tie means the trophy is shared.
Critics argue a single Test is a thin ending to a 2-year championship; defenders point out that knockout cricket forces clarity and creates a Wimbledon-style final.