From my own intuition the words odd and strange can be synonymous depending on the context and could carry very similar meaning in many contexts. I would guess that the word strange is more frequent, but something tells me I might be wrong too. I realise the word odd can carry additional meaning of number so that could significantly increase its occurrence.
The word collocations that I thought of immediately: the odd situation, a strange man.
i) To complete these searches I took following steps: I launched MonoConc application. Chose LOAD CORPUS FILE(S) from the FILE menu. Located and selected folder named Corpus1 and then selected all the files in folder named Speech and clicked Open. Then repeated the same to folder Writing. Once both corpora have been loaded, chose BNC SEARCH from the CONCORDANCE menu, entered the word odd and clicked OK to perform the search. Then I examined the results in the concordance window and repeated the same for the word strange.
ii) I obtained 211 hits of the word odd and 233 hits of the word strange.
iii) Approximate ratio of occurrence for odd compared to strange:
odd:strange = 211:233, which can be reduced down to approximately 4:5.
To calculate this example, I divided the both sides by 50 and rounded to the nearest number (211:50=4.2(4, 233:50= 4.66(5).
i) To produce about 50 hits of both words I chose to run the new search for each word for every 4th hit (as previous results were around 200, dividing results by 4 brings it to around 50). To perform the search I took the same steps as in the steps above only after entering the word in BNC search I expanded the Options Menu at the bottom left corner and typed in number 4 in the graph Every Nth Hit and then clicked OK to close the expanded option and OK again to complete the search.
ii) Those searches gave me 52 hits for the word odd and 58 hits for the word strange.