It has certainly been an exciting first half where for most fans the Indians have played well above expectations. Many come-from-behind wins, walkoff wins, and exciting games just about every night. The Indians have also certainly endured some tough circumstances where their four-game home opening weekend with Seattle in April was snowed out, and then the Indians had to go to Milwaukee to play three "home" games against the Los Angeles Angels.Through it all, the Indians are 51-32, have won six games in a row, and look to finish the first half strong with a six-game road trip at Detroit the next three days before finishing up in Toronto for the weekend. A year ago at this time, the Indians were 39-43 and 16 games out of first place. What a difference a year makes, huh?But, what has been the driving force behind that 11 game improvement to date?The offseason moves made by Indians General Manager Mark Shapiro are certainly a reason for the improvement, but how much really? The Indians went out and acquired Josh Barfield in an offseason trade with San Diego (a good move), and also signed veteran free agents David Dellucci, Trot Nixon, Roberto Hernandez, Aaron Fultz, Joe Borowski and Keith Foulke.To date, however, those free agent signings have had minimal affect on the team production-wise as Foulke retired before even throwing a pitch as an Indian, Hernandez and his 6.23 ERA was released two months into his tenure, David Dellucci's .690 OPS is on the disabled list, and to quote Steve Buffum, "Trot Nixon is a fungus". Only Fultz and Borowski have been effective, although very shaky in the process.The performances of Fultz and Borowski in the bullpen combined with the veteran leadership provided by the likes of Nixon are not nearly enough to catapult this team to an 11-game improvement. Yes, these acquisitions have helped, and probably more from a leadership standpoint, but there are other reasons that have had a greater impact on this team's improvement to date.One of those reasons is several players have had an outstanding first half and put up numbers well above career averages. Some of these great performances have been negated by the Indians having some performance issues from other players, like Travis Hafner and Jeremy Sowers, and have had several key injuries to the pitching staff. In light of this, several players have stepped up and picked up the slack, notably starting pitcher C.C. Sabathia, catcher Victor Martinez, shortstop Jhonny Peralta, third baseman Casey Blake, and reliever Rafael Betancourt. The fact the Indians are in first place has a lot to do with these players stepping up and performing at a level above career norms and picking up the slack for some of the injuries and poor play from other positions.But, just as important as those performances have been, the Indians minor league system may be the biggest reason the Indians stand today at 50-32 and instead are not struggling to stay around .500.While Sabathia has been Cy Young worthy the first half and carried the staff, he only pitches once every five days. Also, with Jake Westbrook and Cliff Lee each being mostly ineffective and missing over a month of the first half with injuries, and Jeremy Sowers being a huge disappointment, the Indians had three big holes in the rotation. The Indians needed someone to step in and save the starting rotation, and that pitcher has been Fausto Carmona. To date, Carmona has arguably pitched at a level well above what either of those three have ever done.Carmona was scheduled to start the season in Buffalo, but an injury in spring training to Cliff Lee put Carmona in the rotation. Since being inserted into the rotation to start the season, Carmona has been a godsend going 9-4 with a 3.78 ERA in 16 starts. While Sabathia has been the ace of the staff, one can say Carmona has been the glue of the staff in that he kept it from falling apart when Lee and Westbrook were injured and ineffective, and Sowers struggled. The emergence of Carmona alone is one of the biggest reasons this team is 11-games ahead of last year's pace.While Carmona clearly has had the biggest impact from Buffalo, there has been a solid cast of other players who have made their presence felt this year. Probably the second biggest addition has been left-hander Rafael Perez in the bullpen. The Indians had some troubles early in the year in middle relief with Jason Davis, Fernando Cabrera and Roberto Hernandez, but since Perez's arrival the middle relief has settled down. To date, he is 0-0 with a 1.90 ERA and 0.93 WHIP in 12 appearances. Perez gives us a quality second left-hander in the bullpen, and now he is being used late in games and performing well beyond his years and looks like a keeper.Then there is Jason Stanford. A pitcher long forgotten by most fans after he was injured in 2004, underwent Tommy John surgery, and disappeared in the minor league system for a few years. After the Indians finally had enough of Jeremy Sowers, they needed someone to step in for a few starts since Jake Westbrook was not ready to come off the disabled list, so they gave Stanford two spot starts and he responded by performing well in both. When Westbrook was activated, Stanford ended up sticking with the team and is a quality long man in the bullpen, as well as a third lefty the team can use.While he has struggled of late, Tom Mastny is another Buffalo player who has performed well when called upon. Mastny was really given no shot to make the team going into spring training, as Matt Miller and Jason Davis were both ahead of him for the final bullpen opening. But, when Foulke retired and Miller went down with a right-forearm injury, Mastny was there to answer the call. Instead of going to Buffalo, Mastny instead found himself on the Indians opening day roster and has pitched well most of the season. He is 5-2 with a 5.23 ERA and 1.68 WHIP, but as mentioned he has had a rough go of it as of late. In April (2.89 ERA) and May (2.84 ERA) he pitched very well, but in June he has struggled (11.00 ERA).Offensively, the Indians have not had near the impact they have had on the pitching front, but there have been some key contributions. With Andy Marte falling flat on his face, the Indians were forced to move Casey Blake out of the outfield mix and to third base full-time. This left a big void in the outfield for a right-handed bat to partner up with veterans Trot Nixon and David Dellucci. While Jason Michaels has done a great job platooning in left field, the Indians needed to find someone to team up with Trot Nixon in right field. That player ended up being Franklin Gutierrez.Gutierrez is having a fine comeback season as a prospect. He is not nearly the mega-prospect he was billed to be a few years ago, but he has proven to be an excellent defender with speed and some occasional pop in his bat. He offers a great defensive solution late in games for the turtle-like Nixon, and even saved a game in Cincinnati with a great running catch into the wall that Nixon would never have caught, and had the deciding home run in a 1-0 win against Kansas City a few weeks back. On the season, he is hitting .288 with 4 HR, 9 RBI and an .844 OPS in 59 at bats.Also, this past week we may have seen the emergence of Ben Francisco. With David Dellucci going down with a hamstring injury, the Indians needed to find someone to pair up with Michaels and share the left field duties since Michaels has proven to be very valuable as a part time player, but very ordinary as an everyday player. Francisco finally got the chance to play this past weekend against Tampa Bay, and responded by going 6-for-10 with 2 2B, 2 HR, and 4 RBI in three games played.And back in May when Nixon was banged up, Shin-Soo Choo got the call for a few games and produced during a key stretch on the road against the Minnesota Twins. In six games, he hit .294 with 5 RBI, and had two big hits with the bases loaded.Francisco and Gutierrez have certainly helped provide some much needed versatility, speed, defense and production to the outfield corners which had been severely lacking with Nixon and Dellucci out there most of the time. As the trade deadline approaches, expect one of these two young outfielders to be on the move, as not only have they impressed the Indians and fans, but other general managers have taken note as well. Francisco or Gutierrez plus a prospect may end up being enough to get us a good bullpen arm.Buffalo has certainly been good for the Indians this year, and this is still without top prospect Adam Miller even throwing a pitch yet for the Indians. Imagine the impact he could have in the bullpen or rotation this year if he lives up to his billing?The success of the Buffalo players just hammers home Indians General Manager Mark Shapiro's belief you need a strong team not only 1-through-25, but also 1-through-40. When you have failures in free agency, you need quality depth in the farm system to help cover up those mistakes. Look at the problems some of the big spending teams like the Yankees, White Sox and others are having. They have been plagued with injuries and some poor performances, and have not had the talent pool to pull from in the minors like the Indians do to help fix those problems.In the end, who would have thought that the biggest impact on the team this year would not come from free agency and trades, but from the Indians own farm system? The prospects that Shapiro and company have been afraid to play are now making a difference, and the result is a team in first place with a handful of games to go until the All-Star break.