The historical context
The NFL’s historical chronology records changes in 1978 concerning receiver contact and pass-blocking interpretation. These provide context for research into passing-era differences. They do not, by themselves, prove that a particular quarterback’s results were caused by a single rule change or that all comparisons across the boundary are invalid.
A clearer way to read the evidence
Treat a rule milestone as one column in a broader comparison. Add schedule length, attempts, team circumstances and the definition of the statistic being used. Explain which evidence supports your interpretation and which factors remain uncertain. The strongest historical comparison makes its assumptions visible instead of hiding them behind the phrase different era.
Keep in your notes
- Record the actual rule milestone.
- Use several contextual measures.
- Avoid single-cause conclusions.