ok so i will first give the decklist i'm playing around with right now, and a couple of comments on card choices before i get to the heart of my post:


//NAME: TPS

//mana
2 Underground Sea
1 Badlands
1 Bloodstained Mire
1 Polluted Delta
1 Tolarian Academy
1 Library of Alexandria
4 Gemstone Mine
4 City of Brass
1 Mox Sapphire
1 Mox Ruby
1 Mox Pearl
1 Mox Jet
1 Mox Emerald
1 Lotus Petal
1 Black Lotus
1 Mana Vault
1 Mana Crypt
1 Sol Ring
4 Dark Ritual

//draw+tutor
4 Brainstorm
1 Ancestral Recall
1 Yawgmoth's Bargain
1 Enlightened Tutor
1 Mystical Tutor
1 Vampiric Tutor
1 Demonic Tutor
1 Necropotence

//utility
1 Tinker
1 Rebuild
1 Brain Freeze
4 Force of Will
1 Chain of Vapor
4 Duress

//power
1 Wheel of Fortune
1 Windfall
1 Timetwister
1 Mind's Desire
1 Yawgmoth's Will
1 Memory Jar

//now you die
2 Tendrils of Agony

and here is the sideboard i have at the moment:
1 Chain of Vapor
1 Rushing River
2 Stifle
1 Spiritual Focus
1 Misdirection
2 Red Elemental Blast
2 Pyroblast
1 Hurkyl's Recall
2 Hydroblast
2 Blue Elemental Blast

so, a couple notes on card choice.  i took out the time walk and replaced it with brain freeze.  i usually only use the walk as a free land drop, which is somewhat useful, but the brain freeze makes it much easier to combo out (4 spells + brain freeze + tendrils = death instead of 9 + tendrils) for the same cost.  the badlands is in there to make the red blasts easier to cast post-board.  

the rebuild i am considering replacing with retract.  in reading jp meyer's newest article on scg i disagree with him about its utility in combo.  it might not add a lot of mana acceleration, rarely equaling dark ritual, but it does add some acceleration and also, more usefully, spells.  spending 1 mana to get 2 or 3 mana plus 3 or 4 spells is fantastic.  the advantage to rebuild is that it also bounces your opponent's artifacts which can be good (or even critical) if he or she is packing null rod, trinisphere, chalice, or sphere of resistance.  so, for now i'm undecided.  i'll just pay attention whenever i draw rebuild and figure out what percentage of the time i'd rather have a retract.

anyway, now i come to the reason why i'm posting.  i feel fairly confident when playing the first game of any match.  i'm fairly good with deciphering the correct path to victory.  my problem is that i'm not very good at sideboarding for the remainder.  when i look at the decklist i don't really see anything that is reasonable to cut.  could somebody help me out?  i'd really like to hear any comments on A) whether any changes should be made to my sideboard and B) how i should sideboard for various matchups (keeper/tog, dragon, stax/mud, o. stompy, tnt, etc).  any suggestions would be greatly appreciated since this problem has been bugging me for a while now.  later -- jake.