1970 & 1971 Topps Scratch-Offs: How do I tell the difference between them?

[caffeine]

I have 3 of these I got in a lot off of ebay some how. I have Glenn Beckert, Sal Bando & Claude Osteen. These cards aren't much older than I am, but I don't know how to tell the difference. They are unnumbered and the few that I saw pictures of online didn't show me a significant difference between them.

Thanks

 

[Scobes]

This is from Beckett Online and should help:

"1971 TOPPS SCRATCHOFFS: These pack inserts featured the same players are the 1970 Topps Scratchoffs. However, the only difference is that the center of the game is red rather than black."

Scobes