Both captains will have likely learned from past mistakes and given their pairings time to get used to a different ball. But getting it wrong can be catastrophic, as proven by both Mickelson and Woods 19 years ago.
Not having the one-ball rule in effect makes it easier for players to correct any issues that crop up on certain holes. However, there will still be an element of uncertainty and unfamiliarity from some players when they look down at a ball they’re not used to playing with.
Which balls each Ryder Cup player is using
Titleist Pro V1x = Aberg, Fitzpatrick, Hatton, Cantlay, Clark, Spieth, Thomas
Titleist Pro V1 = Hovland, Scheffler, Harman, Homa
Callaway Chrome Soft X = Hojgaard, Rahm, Burns, Schauffele
Srixon Z-Star XV = Lowry, Straka
Taylormade TP5x = MacIntyre, McIlroy
TaylorMade TP5x Pix = Fleetwood, Fowler
Titleist Pro V1 Left Dot = Rose
TaylorMade TP5 = Morikawa
Srixon Z-Star Diamond = Koepka
