The "Wrens" was a division of women Navy sailors who played WW2 war games to identify how German UBoats were so successful. Played many scenarios, and replayed events after attacks to understand German tactics. Would get called in to game out live events as they were happening to decide upon the next day's strategy. Arguably led to enormous increases in British naval effectiveness.
One little writeup I could find on it: https://www.historyextra.com/period/second-world-war/real-li... . Little blurb from the page:
The Game, as it was to become known, took over the top floor of the building, which came to look like a cross between a school gym and a child’s nursery. The floor was covered in linoleum and divided into painted sectors. On this make-believe ocean, the Wrens moved miniature convoys – model merchant ships and their battleship chaperones – according to directions given by the officers taking part in the exercise. But while the Wrens were permitted a bird’s eye view of the play area, the naval captains were allowed only occasional peeks through holes in canvas booths, arranged at the side of the playing field, positioned to recreate the limitations of visibility at sea.
...During the post-mortem that followed each game, all of the players would be treated to a bird’s eye view of the battle. The officers could at last see the tracks of the U-boats drawn on the floor in green chalk, set against the movements of their own ships drawn in white, and learn from the umpires whether or not they had managed to sink any submarines. Often, the officers would realise that they had made numerous dreadful mistakes during the Game, which might have resulted in the loss of their ships in earnest combat.