Win Without Finishing

[wizard1]

16a employee's performance review (9) a-a-a---- 20a great wave (5) s---e 18a mad behaviour (9) c---i-e-t 28a belonging to several people (5) ---r

[Psybbo]

28 their

[bibblebub]

18a) craziness
28a) their

[Mamyalynne]

20 surge

[Psybbo]

20 surge?

[bibblebub]

20a) surge ?

[boxtops]

16a appraisal (answered on earlier thread)
20a surge

[wizard1]

thanks a lot, one more please 26d zilch (4) -n-o

[bibblebub]

zero - if the N is wrong

[shoota]

Zero?

[Sam1960]

could be zero if your n was wrong !!

[shoota]

http://www.thefreedictionary.com/zilch

[factor-fiction]

Where was the N from in 26d, please.

Incidentally, I've always wondered why the crossword has this name- does it mean you can send it off and still might win even if it's not finished?

[Psybbo]

Why does the name remind me of 'Nights in White Satin'?