Yes and no. QB traits play into it a big deal, and QB's that have the ideal or oblivious trait tend to take more sacks. Also, QB's who scramble a lot have a slight tendency to run into defensive ends who push the offensive tackle back.
In my online franchise, through Week 15, my team has 58 sacks, which leads the league by about 10, but I sacked Cam Newton 12 times in one game, and Johnny Manziel 8 in another, so that accounts for 20 sacks alone. I've had a few games where I've gotten zero or one.
In my testing, turning up the computer pass blocking too high results in a total inability to get pressure (you will still get the odd sack from a mistimed scramble or HB screen gone wrong), which makes the CPU QB complete 80%+ of their passes on a consistent basis. With my sliders, if a QB feels pressure (human or CPU), the throw has a good chance of being inaccurate.
Out of curiosity, who are you playing as?