I am using Transmission 1.50b2 (7735) to download a torrent which consists of multiple files. The piece size is 4GB and the approximate length of each file is 350MB so each file consists of about 90 pieces.
This particular torrent has about 60 seeds and 850 leechers.
Transmission tells me that progress is 19.2% complete and that I have 602.9Mb (44MB verified in 11 pieces). It has stayed at (44MB verified in 11 pieces) since shortly after I started downloading. If 44MB verified in 11 pieces is actually true this means that there is a large number of pieces which Transmission has partially downloaded (at least 144 pieces). I obtained these figures after selecting "Verify local data". I have no way of telling how complete all these partially completed pieces are.
I am currently uploading at the rate of 20KB per second. The Upload/download ratio is 2.28. I am assuming that Transmission only offers to upload those pieces which it has verified the hash for the piece. This means that only the same 11 pieces are being offered to other peers in the swarm.
I suggest that Transmission needs a better algorithm to so that it prefers to complete pieces so that these can be offered to other peers in the storm.