The most significant limitations of the 4-3-2-1 point count are:
- Aces are worth more than 4 points (at least 4.2 and maybe more).
- Queens are worth less than 2 points; Jacks less than 1.
- Tens and nines and eights often add significant value.
- Face cards are worth more when they are in your long suit(s).
- Face cards are worth more when they are together in the same suit.
- Generally, a hand with 4-3-3-3 shape is worth less than its point count.
To be clear, we think that the 4-3-2-1 point count is very valuable and we use it heavily. But we apply a lot of judgment.
For more information, see the introductory Valuation Exercise at the start of Real World Bridge 6: The Game Zone.