Wildcard → Lag Board → Frank Thomas
Frank Thomas vs Ken Griffey Jr
1990 Leaf #300 against 1989 Upper Deck #1 — measured, not predicted.
Not currently priced Same era Baseball
- Ratio now
- —
- Baseline
- not established yet
- Vs baseline
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- Observations
- 0
- Ken Griffey Jr, 30d
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- Frank Thomas, 30d
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Not enough observations to draw a history yet. The index records one ratio per pairing per scan; this chart appears once there are at least two.
Every recorded observation
Why these two
The two rookie cards most associated with the premium-set boom that Upper Deck started in 1989 and Leaf followed in 1990 — bought by the same collector rebuilding the same childhood.
What would make this wrong
Both are high-population cards where grade migration, not demand, drives most of the price action. A ratio between two of those is measuring the graders as much as the market.
How this is measured
Each scan records one number: the fair value of Frank Thomas's 1990 Leaf #300 divided by the fair value of Ken Griffey Jr's 1989 Upper Deck #1, both from comparable sales. The baseline is the median of those observations over 90 days — excluding the most recent 21, so a fresh move cannot drag down the very number it is being measured against. Below 8 observations there is no baseline and this page says so instead of showing one.
The baseline is never authored. It is the median of what was recorded, or it does not exist. Nobody types a target ratio into this system.
This is an observation about a historical relationship, not a forecast. A gap that never closes means the market permanently re-rated Frank Thomas rather than temporarily forgot him — that is the risk in every pairing here, and it does not mean-revert on a schedule.