Speed ratings

The Xp path reward is an 87 Celebrini. His speed rating is 87. The 83 version of this players speed rating is 86. We have all seen in the past how speed ratings on cards increase as the rating of the card does. So what weird formula is EA using to adjust this ability. I have 78 and 79 player cards. No big name players. With speed ratings of 88 an 89.  So EA. Are you randomly picking numbers or is there a concrete formula you use. Because as I see it in this game. Your just tossing  out numbers.