When talking about Nic-Fit it doesn't necessarily specify what list your opponent runs, there's almost as many versions as there's of Delver: Junk-Nic-Fit (Knight of the Reliquary, Siege Rhino), Jund Nic-Fit (Grove+Punishing Fire, Primeval Titan, Kessig Wolf Run), classic Nic-Fit (Hymn to Tourach, Liliana), BUG-Nic-Fit (Birthing Pod, Strix, Shardless Agent) or 4-color-Nic-Fit with Knight and Grove.
Also some people run Sylvan Library with Toxic Deluge, others run Sensei's Divining Top with Pernicious Deed (so you don't hit you card fliter).
It seems that your opponent played Knight and Pernicous Deed, but no Grove.
With my deck (
http://www.mtgthesource.com/forums/s...l=1#post931068) I'd sideboard:
-4 Wasteland (he plays a lot of basics, I want to keep him off explorer with Stifle)
-4 Daze (getting bad reeeally quickly).
-2 Lightning Bolt (as you said: not that great, I'd rather throw in my YPs aggressively once I've generated 2-3 tokens so I can attack with those later)
-1 Forked Bolt (he hardly has creatures with 1 power, I'd rather kill a Siege Rhino with 2 Tokens blocking, a Titania, Thragtusk or a small KotR)
+1x Pithing Needle (good against Knight, Pernicious Deed, Top)
+1x Invasive Surgery (Toxic Deluge [propably doesn't have any though], Green Sun's Zenith is his best spell)
+4x Cabal Therapy (Get him! Name the cards you're afraid of and can't deal with your current hand. Good targets are 4-ofs like Veteran Explorer, Green Sun's Zenith or KotR)
+3x Abrupt Decay (good against Knight)
+1x Virtue's Ruin (good against Knight, Sigarda, Siege Rhino)
+1x Tropical Island (KotR-versions sometimes run wastelands so they can waste out their opponent)
Note that I'm actually leaving in the Force of Wills. Sometimes they run 1xCavern of Soul, sure, but their creature types are very diverse. Killing especially their sweepers can prevent them from 2-for-1-ing you, so it's not even like you'd have better card advantage without FoW. You lacking need of lands makes up for the disadvantage.
Also while Krosan Grip can be good against Top and Pernicous Deed it just has too few targets. Since they play no card selection it could very well be that they just don't draw a card I want to target the entire game.
Taking a look at your list and sb I'd suggest the following:
-1 Spell Pierce (can catch him off surprise, but once he knows you play it he can play around it rather easily)
-3 Wasteland (see above, I'd leave 1 in against unexpected stuff and because your curve goes up a bit)
-4 Daze (dead too early, they can play around it when they know you have it because of Therapy)
+1x Grim Lavamancer (careful with your x-1s, they propably have Golgari Charm in the board)
+1x Pithing Needle (KotR, Scavenging Ooze, Top, Deed)
+2x Cabal
+1x Winter Orb (their spells cost a lot of mana, should be fine)
+1x K-Command (2-for-1s are great in this matchup)
+1x Fire Covenant (x-for-1s are even greater)
+1x Grafdigger cage (stops Green Sun's Zenith and Cabal Therapy flashback. Why do you run this card when you play Therapy yourself?)
This matchup is all about high impact spells. Soft-counters are often dead because your opponent can play around them, so you want to trade with him and get card advantage, the fact that you can filter through your deck better with cantrips should give you a good chance in the long term.