In a tetraploid B/B/b/b, the number of possible quadrivalent pairings would be one. Only one possible quadrivalent can be formed. This quadrivalent would have 50% of recombinant products.
As shown in the figure, the number of quadrivalent pairings in a tetraploid would be one.
The possible pairings are shown in the figure below:
From a tetraploid:
• Two bivalents can pair
• One quadrivalent can pair
• One univalent and one trivalent can pair