There is no bottom or middle of the sales funnel without the top. When it comes to making their numbers, most of the challenges sales organizations face involve weakness at the top of the funnel. It's not that they aren't good salespeople or that they lack good processes and methodologies. Most of the time, what is holding them back is not having enough opportunities to begin with.
The problems you experience in the middle of the funnel usually fall into one of two categories. The first class consists of non-opportunities. These are the deals that aren't really deals at all. Maybe you mistake receptivity for a compelling situation which might prompt your dream client to make a move. This problem is easily solved: Push these non-opportunities back to the leads category where they belong.
The second group consists of stalled opportunities. These opportunities are usually missing some of the commitments necessary to move them forward. This problem can also be solved (albeit not easily) by good coaching and some big conversations with your prospect.