So how would you go about making an educated reverse engineering claim on the stake at risk without knowing his other legs nor expiry dates? Is it even possible? How about a wide range?
For example, a $450 put for September 17th 2021 would cost about $16.70 per share:
https://finance.yahoo.com/quote/TSLA/options?strike=450&stra...
One option counts for 100 shares, so that would be a (8001 * 16.70 * 100) 13.36 million dollar bet. Suppose that TSLA is worth only $400 on that date, with your right to sell at $450 you'd be in the money for 40 million dollars, or roughly $26 million in profits. If TSLA is worth $450 or more on that date, your options expire worthless.
You can't figure out his position with this information.
For example, you could buy very, very out-of-the-money puts for a penny. (Your bet would basically be: TSLA loses 95% of it's value in the next week.) My total value at risk for this bet (of 8,001 put contracts) would be $80.