Can someone please explain the deal with these three.

Are they a series of some sorts? Each has 33 cards.

Probably the most disliked and uncollected of all the E-sets due to the repeated use of art that created situations where the image isn't the actual player. Art was used once in set A and then repeated 2 more times with new team names and player names added in sets B and C. See Below for an example.

33 different images were used to create the 99 total cards. Of the 99 cards there are only 78 different players.

1908=a
1909=b
1910=c
33 cards per set, per year with generic pics of players

Thank you!