Ok, so I kind of promised myself I wouldnt go here, but I feel this has to be broken down once and for all. Firstly, you cannot compare the simulated side of shooting in PES 6 to PES 2011, they are light years apart with regards technical reconstruction. PES 6, in my opinion, was as 'Arcade' as PES got in Old Gen. I bought it and played it prior to the release of PES 2011, and I found it to be dated and unrealistic in so many areas it was actually quite shocking. It still followed the basic principles of striking, but there were far less relevant contributing technical factors that you were required to adhere to, in order to strike the ball cleanly. Without going into exactly what it lacked, I'd prefer to highlight what is instrumental in PES 2011, and you can deduce the differences yourself.
The shooting system in PES 2011 is incredibly advanced from a technical simulated perspective, and unless you truly grasp it's relevant idiology, I can appreciate it may well feel very random to you. This randomness is derived from the huge amount of variables that this system can produce. Nothing more, nothing less. It's the understanding of these fundementals that will help you achieve your goal, pardon the cheap pun. Like I have said many times before, and it's the classic footballing cliche, but there are no guarantees in football, nothing is ever certain, all you can do, is give yourself the best possible foundation for the strike, and the rest is in the hands of each players own technique, and the lap of the footballing Gods.
When shooting a ball in real-life, your power isnt generated by how hard you swing your leg, it's by the smoothness of the motion, the follow-through of the strike, and technical prowess. Other factors that contribute massively to a clean strike are are body-posture, body-balance, preferred striking foot, timing, angles, the distance from the ball, and the position of your standing leg. In order to give yourself the best possible chance of a clean strike, all of these factors need to be in place, in real-life and in PES. And the way in which PES replictes this is exact philosophy is quite staggering, and in a word, genius.
The varying results of a strike in PES all relate to everything I have listed. The randomness, when all relevant techniques are in place, then comes from the individual nature of each and every player. PES has a plethora of statistics that massively vary from one player to the next, and for the most part, it's these statistics that are paramount in deciding the relevant outcome. The worlds greatest strikers are defined by their ability to be able to find that clean strike, when the basic fundementals are stacked against them. By this I mean, the ability to strike a ball cleanly when their body- balance, body-posture or the best angle isnt available to them. Players that manage to be able to create power and accuracy when they have to 'dig the ball out of their feet' or react and address their stance in a split-second from an unfavourable bounce or ricochet. This is what great strikers are capable of, if you like, they have the ability to over-ride basic fundementals due to superior technique.
These type of players are highlighted very well in PES. The likes of Torres, Drogba, Messi, Ronaldo, Villa, Rooney et al, are all capable of producing clean strikes, shots, without really needing to adhere exclusively to all the basic fundementals. This is what seperates them, this is what makes them God-like in comparison, and why I hate playing with them, or against them, very little thought required.
Being aware of the player that your trying to shoot with is half of the skill in PES, the other half, is just following basic fundementals. When it comes to shooting in PES 2011, 99% of the time, if I hit a poor strike, I know exactly where I went wrong technique-wise. PES get's this so, so right, it's just a shame that not everybody can see or appreciate it's beauty, for whatever reason that maybe. I read alot of people commenting on that fact they only need to press the shoot button for a very short time to gain maximum power, and sometimes they have to hold it down longer. This actually has nothing to do with how long you press the button for, the deciding factor here is completely relevant to position of the ball, distance from the player, body-angle, body-posture, and the player your controlling.
In real-life, in order to get a good, clean powerful strike, you need space and time for the most part, but not all. (Again see Elite players and momentum and inertia). The follow-through of the strike is what gives you the power, just as much as where you connect with the ball. Running onto a strike, with a 2-3 foot stride pattern will, if your technique is sound, will give you a powerful shot. Also, using the momentum of the ball coming in your direction utilises physics to enhance the power. Hence the reason you see players have freekicks 'rolled' back to them, or really powerful strikes from first time shots outside the box, from the likes of cleared corners etc. Just make sure the ball is out of your feet, your body angle is good, your not under pressure. If the ball is 'in your feet' then the chances are your power is produced via either a snap-shot, or you leaning back. When leaning back, control is compromised, and you more often than not will see the ball rise.
There are so many different way's to shoot in PES. The shoot then R1 dink shot is a brilliant way to finish in very tight situations. The timing needs to be perfect, especially against the better goalkeepers, as they stand tall till the very last minute. Pressing shoot with L1 held for a chip shot is another great way in which a players vision can be rewarded. It's one of my favourite ways to score, and with players with high technique, a great weapon. For those of you having trouble with finishing inside the box, the 'Controlled' shot works well. Pressing shoot followed immediately by R2 will sacrifice power for accuracy. These are all different ways to shoot, for different situations.
Like I said, I have no problem whatsoever with the shooting, it does exactly what I ask it to achieve. The varying results are based on each individual player's ability. Knowing each player and what he is capable of on PES is a skill in itself, but get the basics in place, and you shouldnt have any issues.