won_LTO integer won last time out (yes = 1, no = 0)
won_PTO integer won penultimate time out (yes = 1, no = 0)
won_ATO integer won antepenultimate time out (yes = 1, no = 0)
so it's LTO, 2LTO, 3LTO
All table field definitions are given here:
https://www.betwise.co.uk/data_download/historic_runners_insights