[hempick]

1989 Topps Baseball...   Ken Griffey Jr. missing from the base set?  They had to stick him into the Traded set for that year because he didn't make it into the regular issue that year.  He was the #1 overall pick in 1987.  Donruss had him in the regular issue, Fleer had him, and Upper Deck had him.  Somehow Topps didn't have him in the regular issue.  Score only had him in the Rookie/Traded set, but I mean...  Topps is Topps.  How did they miss having him?!

1991 Topps Football...   Brett Favre missing from the base set?  Pacific's base set had him.  Pro Set had him. Pro Set Platinum, Score, Topps Stadium Club, Fleer Ultra, and Upper Deck all had him.  Action Packed had him in a Rookie/Update set.  Topps didn't.  Neither did Fleer.  Now I get that Favre wasn't as heralded when he came into the pros as Griffey was, but still it seems like an egregious omission.

1990-91 Topps Hockey...   Jaromir Jagr missing from the base set?  Score had him, Pro Set had him, OPC Premiere hade him, Upper Deck had him.  Not Topps, though.  They even somehow missed him in their Bowman release from that year and Bowman is known for being the set to get for rookie cards.

I'm sure there are plenty of other similar instances of stuff like that happening.

...but how?

Trying to cut costs?  Purposeful omission? Accidental omission?

Anyone have any ideas?

[bonds20001]

I think that Topps puts it's checklists together sooner than others, so they miss some players. 

Also, from a blog last year:
My guess is they knew the base set was going to sell no matter what. There was no need to incentivize the base set. At this point (between 1988 and 1989) Upper Deck hadn't thrown the proverbial gauntlet down and Topps was just cruising along as the #1 brand with the #1 market share. Might as well save Griffey for the Traded set, which is almost exclusively hobby, and relies much more on pre-sale orders.

Topps didn't miss again though. In 1990 they made sure to get as many rookies in the base set as possible and truly left just the call-ups for the Traded set. Oddly enough, Upper Deck is the one that whiffed on getting Frank Thomas in their set in 1990, not Topps.

[hempick]

I think that Topps puts it's checklists together sooner than others, so they miss some players. 

Also, from a blog last year:
My guess is they knew the base set was going to sell no matter what. There was no need to incentivize the base set. At this point (between 1988 and 1989) Upper Deck hadn't thrown the proverbial gauntlet down and Topps was just cruising along as the #1 brand with the #1 market share. Might as well save Griffey for the Traded set, which is almost exclusively hobby, and relies much more on pre-sale orders.

Topps didn't miss again though. In 1990 they made sure to get as many rookies in the base set as possible and truly left just the call-ups for the Traded set. Oddly enough, Upper Deck is the one that whiffed on getting Frank Thomas in their set in 1990, not Topps.

Ah, so it was essentially a marketing ploy. The base set would be bought so why even bother worrying about it. Interesting.

Good point about Frank Thomas not being in the 1990 Upper Deck set. Donruss and Fleer both missed him in their base sets that year, too.