Jeffrey Donovan at the The Pro-Mash website explains the finer points of "no-sparge" and "first-runnings" brewing:
No-sparge mashing is simply collecting the first running from the mash tun as opposed to sparging out the additional sugars . . . 'Pure' no-sparging is to simply take the first running when the mash is complete. 'Batch' sparging is to add an additional infusion of water at the end of the mash, but to sill not-sparge the mash in the traditional 'rinsing of the grains' fashion.I usually batch sparge because I can still taste the sweet sugars in the malt after taking the first runnings. I have to decide to let that go this time and simply blend whatever I get with the black liquor I make it the kettle. When I top it off I will know the expected gravity and decide on the hops. I think I'll stick with the high-alpha Admiral variety that I've used before. I want a grain flavor, with just enough hops to balance the malt. I don't want to taste the hops so much as notice the clean bitterness. It is a tough thing to get right. Sounds like a great way to spend a Sunday.