But some folks -- incessant tinkerers and other assorted ne'er-do-wells -- ponder whether or not the predictability of the standard Speed Chart is a good thing, and mess around with ways to change it. Phaser is one such way...
What's the point? Well, with the randomly-generated -- but unique -- Segments in hand, you could now use these Segments as the character's Phases in a Turn, instead of using the Speed Chart (which always gives characters of a given SPD their Phases on the same Segments, of course).
It also takes a number of Turns, so you can generate many Turns worth of Phases at once. This is useful for readying a list of Turns in advance, and just checking them off as you use them.
This all sounds more complicated than it really is. Just try the silly thing. You'll see what it does.