Legal Question in Criminal Law in Texas

I think that I have already answered this or perhaps it was on AVVO.

The amount of time that your friend will serve depends on his crime. If it is an aggravated offense, then he must serve 1/2 of the time (25 years) before even becoming eligible for parole. This is flat time. It does not matter what his time sheet says about the amount of time he has accrued.

If the crime is not aggravated or one of the specifically enumerated offenses like murder, then there is no limit on the amount of time he must serve and he will accrue good time (as long as he does not get into any trouble) towards his sentence to be paroled.

As far as time reductions - they really hardly exist. It takes the agreement of 2 of 3 officials which include THE DA, THE judge, and / or THE sheriff. The only time I have seen it occur in my 23 years of practice is once when a guy gave significant information against many members of a gang (and he was serving a non-violent offense) and once when a guy was on his deathbed (and was costing the state a boatload of money for medical care) and he was released to the VA where he died a few weeks later.