For much of Bolton's 2011/2012 Premier League season, Darren Pratley was very much a bemoaned figure. The player that played such a large part in Swansea City's promotion to the Premier League looked like a shadow of himself when making the jump on his own, signing for Bolton Wanderers on a free that summer. Pratley never really managed to truly find his feet in the Premier League despite looking a much improved player in the latter stages of the season. As a result, he was constantly on the receiving end of jeers from the home fans.
His performances really were nothing special, save for a crucial goals against QPR at the end of the season and a goal against Swansea in the FA Cup, but it wasn't for a lack of trying. While Darren Pratley isn't the most technically skilled player and often has trouble hitting the broad side of a barn with the ball at his feet, he's grown into a massively important figure for Bolton Wanderers.
Pratley doesn't really assist goals (only two on the year) and doesn't score them (only one there) but he will run himself absolutely ragged. He will get himself up and down the pitch and he will do it for 90 minutes. When Darren Pratley makes an appearance, Bolton Wanderers are very much better for it and the numbers back that up. Keep in mind that correlation does not equal causation but this is one hell of a correlation.
In the league this season, Darren Pratley has made 26 appearances, split roughly down the middle between substitutions and starts. His chances were sparing under Owen Coyle and grew in frequency under Dougie Freedman to the point where he has started the last 15 matches (in all competitions) consecutively and going the full 90 minutes in all but three of those.
In those 26 appearances, Bolton Wanderers have managed 13 wins (50%) and have picked up 45 points. That's an average of 1.731 points per game. There have been 15 matches this season in which Darren Pratley was either not named to the team or was an unused substitute on the bench. In those 15 matches, Bolton Wanderers have managed 12 points total for an average of 0.857 points per game (slightly less than half of what the team has earned with Pratley appearing). The Trotters have managed only two wins (Derby County and Charlton Athletic at home) in those 15 for a win percentage of 14.3%.
The explanation for those differences isn't from a goals scored persepective. In Darren Pratley's 26 appearances, Bolton Wanderers have managed an average of 1.423 goals per game. Without Pratley, that number is actually higher at 1.5 goals per game but the figure is boosted slightly by the away loss at Peterborough where Bolton scored four. Without that match, the number drops to 1.308 goals per game (17 goals in 13 matches). It's not a massive difference.
Of course, Darren Pratley's involvement isn't the only explanation for the massive gulf but there isn't a question about how much of a boost he can be for the team. Darren Pratley is not a world-beater nor will (likely) be the subject of a massive Manchester City bid. Instead, what Darren Pratley has become for Bolton Wanderers is a workhorse and one that is willing to leave everything on the field and when all is said and done, that is what Bolton Wanderers fans should really be asking for.