XF Rubik is one of the two most frustrating openings to play against (the other being XF Lerpy) since (1) there are some well-mapped lines that violet can play automatically to win by a good-to-excellent margin and (2) it’s not obvious what to do to make the loss at least up-for-grabs rather than inevitable if violet is at least moderately competent (or has a memory stocked with the more common lines). Anyway, here are two lines of defence that I think were examined a year or two ago, discarded, but have been revived. Like most old/new lines they may be flawed but since the exact reasons why they are flawed are now forgotten (or were worked out by players who are no longer frequenters of the site) and since blokus strategy has gotten subtler over the years, they are definitely worth a second look. At the moment they’re having a lot of success on the site but… well, now I’ve written a post I’m expecting that they will get a little less successful.
The bottom one looks better, since the 1-2 series of holes created to the left of orange F is something one instinctively avoids in duo. Yet the first one does force violet to play the ugly I5 on left if he wants to stretch past it. The good thing about both of these ones is that violet F is easily cut off & so violet is tempted to defend on right on move 3, & if that occurs orange has a lot of strong moves on the left (probably Y or L5), & I think the game is orange’s to win then. But I think the circling game doesn’t look great for orange: here’s a line that works with either positioning of orange F:
(Note that if orange plans to block on the bottom on turn 4, then orange Y should probably be L5 or even a kiss move like T4 or T5. But that looks kinda suicidal to me.) Anyway, so violet’s got two perfect series of jaggies for orange to climb over, & meanwhile violet has lots of nice moves on either side: Z5 or W on bottom, L5 kiss or hang on top. Am I missing something or is this a writeoff?