Btw. my tips might not working that effectively on Derezze [DM] but they perfectly suit for Disc Arena [DA]. When ur opponent constantly is blocking like having "autofire" activated on a joystick, then u automatically start to guess him as indefeasible. Wrong thought.

Short History:
When i started to play the first Tron 2.0 demo on July 2003, blocking indeed was an offensive powerful weapon back in time because when u blocked in the correctly direction, the opponent could have lost alot of energy which made the game pretty unbalanced & easier to play for those who failed to aim properly. Ladies & Gentleman...this was the decade of the "so called" Blockwhore.

More than a half of programms gave big hopes in the gold release of Tron 2.0 to have this & other annoying bugs vanished. Blocking in the full game became lesser attractiv but it turned out that to be still useful thanks to the perplexity of some players. Endlessly controversy then happened on serval forums as also within the spectator rooms on gamegrid & this was significant for a clan named Block Union BU somewhen between 2004/2005. If i don't fail to remember the founders nick was Hack who wanted to siganlize for everyone a freedom of choice instead to forbide an implemented feature ingame to use.
HOWTO derezze a Blockwhore:
The easiest opponent would be someone who took a fixed place. If u face an opponent such this level u don't need to move neither. Proceed the following steps:
a) press the left mouse to release the disc but keep holding the button
b) while u hold the button move a little bit with ur wrist to steer ur disc to a desired angle.
c) u will recognize the disc can curve arround the players back. In this situation the blocking player is helpless as the disc will hit him in the back when u stop holding the left button (Backshot). Be carefuly using time...after a certain amount of time the disc automaticaly will fly back into ur hands. The Discplayers call this a recall.
A few Backshot-methods available:
I discovered this technique from Xistence who always has been an inspiring factor to me. As there are availble a few variations of backshots i named the above-mentioned mehtod simply as "curved Disc". The most used option by the crowd was to release a straight-lined disc by quickly pressing on the left mouse, guessing then the aiming point where the player soon to be arrive & then after calling back the disc with the right mouse. This method is useful when ur opponent is an Jump 'N' Run nature but when he is blocking often it will result to endless losses of ur disc. The advantage he will take is the very moment when u have lost ur disc for a few seconds. During these seconds expect him to shot with his disc. Dodge while u wait for the return of ur disc.
It is possible to avoid the situation i told already. For a better insight of this theory let's take for example Disc Arena 1. Sorry for causing u a little brainstorming. Both sides have 2 big platforms to stay. Procced as above-mentioned with the difference that this time u are gonna to care for the best position too. Which means u will have to move ur avatar aswell in order to ehance the scope of ur flying disc, to bring therefore urself into an accordant position, which will be changed as often as ur opponent is changing his position. This is very necessary ! For example...u are on the right platform & ur opponent is about to make a step to the left. Of course...this requires u to shape ur sense to predict the moves correctly.
The difference between a straight-lined to a curved Disc that the curved Disc won't hit him on the front side. So in our example...while our opponent is about to move to the left ur disc will fly arround him & give him a backshot when u didn't fail to guess his objective destination. A straight-lined shot would be to risky because when he kept blocking while u have fired on him, the chances u get blocked are too big. Allthough this might be easier to manage as to curve ur opponent but in exchange it doesn't feel like a gamble such the Russian roulette.
Questions
By chance if u don't understand my explication u may ask me in this thread. The best way to understand some theory is to make or at least to imagine the praxis.