I don't think combining the V and Z would be a good option.

The only reasons I am against an M-V combo is because I have plans for the V line in terms of fantasy extensions.

The reason I am against the V-Z combo is that I ave extension plans for both lines.

Considering how New York has changed since 1976, might a (V) - (Z) combination be good with possible expansion to midday service between Essex Street and Jamaica Center and evening service to Second Avenue? I would consider keeping either the (V) or the (Z) letter for the combined route.

I am the same way, but the letters of the lines could always change.

With and V/Z combo it just makes the route too long and goes in almost a complete circle.

With an M/V combo, the line isn't as long, even though it is still almost in a literal circle.

Perhaps a V-Z-L combo from Canarsie to Forest Hills via Willy-B and 6th Avenue? (Would there even be enough capacity on the Willy-B for the J/Z, M, and V?)

The thing is, even though the M/V route is roundabout, it's not meant for "terminal to terminal" riders. It functions like the current (V) while giving Metropolitan/B'way Bklyn riders one-seat Midtown access. What's more, since Qns Blvd - Midtown riders and Metropolitan - Midtown riders ride in opposite directions, IMO crowding won't be too big an issue, even with increased ridership.

Well said. Exactly, the point of that combo is not for a person to ride the whole line from terminal to terminal, but to maximize use on both ends as middays:
M ends at Chambers, V ends at 2nd Av. It is no wonder they are practically empty by the time they reach their terminals as the riders would take the J/4 or F respectively to continue further.
Now having the combined route you allow M riders to go directly to Midtown without having to transfer to the L [M riders stays on M and not transfer at Myrtle-Wyckoff] or F [riders don't have to transfer at Delancy-Essex] and the V side would finally go to Brooklyn, which should make it at least more useful than everyone waiting for the F to show up.
Final point by combining the lines you trim off some stations on each lines and the M running 8-car trains you then have to make the 'V's end' run 8-car 60' trains as well meaning a surplus of cars to give to say the G line.
This is why such a plan should be looked into.

No doubt midtown service on ANY of the Nassau St. lines would be a huge improvement over what we have now but I agree with most of the posters here: it would be best if that line were the (M) since it would help relieve crowding on the (L).

Of course, I don't think this is going to happen for the simple reason that Park Slopers want the (V) for themselves. When I brought up the idea at the Transit Riders' Forum a few months ago that's basically what I was told. Never mind that they already have midtown access and giving them the (V) would only enhance their service, whereas combining the (M) and (V) would create a brand new and much needed service; they're Brooklyn, they have clout.

I wonder, though, if it would be possible to do BOTH. Run the (V) to Church Ave. and modify the (M) to run uptown along 6th Ave and then CPW, terminating at 145th St. Does anyone know if this is technically possible?

And assuming it is, how does one go about getting the MTA to implement the change in our lifetime?

And even that looks like it won't be possible; revised SAS plans eliminate the third track at 72 St.

Also, why squeeze a new line down 6 Ave when you could just combine (M) with (V), thereby eliminating the squeeze?

Where'd you hear that at? The last plan I heard (from last year), a third track wasn't going to open until the line went below 63rd. (Phase 3) Could you have been reading about phase 1 and thought it was omitted for good?