There's a good amount of subjectivity regarding baseball prospects. With the evaluation of talent being in the eye of the beholder, finding consensus is often difficult. Even Jim Callis and Jonathan Mayo of MLBPipeline.com don't always see eye to eye. They discuss their viewpoints regularly in a feature called Pipeline Perspectives. Submit a topic for them to debate.

Enduring a slow and painful rebuilding process, the Cubs are headed for their fifth consecutive fifth-place finish in the National League Central. While the Theo Epstein/Jed Hoyer regime has made finding pitching a priority since taking over in October 2011, they're actually doing just fine in terms of run prevention.

Chicago ranks 10th in the Major Leagues with 3.9 runs allowed per game, ahead of three of the 10 clubs that would make the playoffs if the season ended today. Scoring runs, however, has been another story.

Despite the presence of building blocks Anthony Rizzo and Starlin Castro and a surprisingly effective performance by journeyman Luis Valbuena, the Cubs have managed to score just 3.9 runs per game, the seventh-worst figure in baseball. That's actually an improvement for Chicago, which had the third-worst offense in both 2012 and '13.

Help is on the way, however. The Cubs have the best crop of position prospects in any farm system, and their Triple-A Iowa affiliate has the most promising lineup of any team in the Minor Leagues.

Jonathan writes that Oakland's Class A Advanced Stockton team has the top prospect lineup in the Minors, and I'll grant that the Ports do have the deepest lineup. But when it comes to impact, no one can top the I-Cubs.

And, no, I'm not counting player/coach Manny Ramirez and his 555 big league home runs.

All kidding aside, Iowa does have the most devastating hitter in the Minors in third baseman Kris Bryant. The No. 2 overall pick in the 2013 First-Year Player Draft, he led NCAA Division I with 31 home runs last spring -- more than 223 of the 296 Division I teams hit. Bryant went deep nine times in his 36-game pro debut, then he topped the Arizona Fall League with six long balls.

That adds up to 46 homers last year, a total Bryant might surpass in his first full pro season. The 22-year-old opened 2014 with 22 homers in 68 games at Double-A Tennessee and has hit six more in his first 15 games in Triple-A. He has everything a power hitter needs: size (6-foot-5, 215 pounds), strength, bat speed, loft and patience.

Now hitting .353/.451/.713 overall, Bryant has surpassed shortstop Javier Baez as Chicago's top prospect. Baez has struggled for the first extended period of his pro career since signing as the ninth overall choice in 2011, batting .240/.307/.433 with 100 strikeouts in 75 games for Iowa.

Though his numbers aren't as pretty as Bryant's, Baez remains an elite prospect. After all, he's the youngest regular in the Pacific Coast League at age 21, and he still retains what may be the best bat speed in the Minors. He's able to barrel balls out of the strike zone, but Triple-A pitchers are beginning to educate him on the perils of chasing pitches.

Bryant and Baez give Iowa the most dynamic duo of position prospects anywhere, and one day, they could bat third and fourth for the Cubs and combine for 70 or so homers on an annual basis. Iowa also has the top second-base prospect in the Minors. With Mookie Betts getting promoted to Boston, that distinction now falls to Arismendy Alcantara.

The 22-year-old Alcantara keeps getting better and better, and he's in the midst of the best season of his six-year career. He's hitting .310/.350/.546 and paces all PCL hitters in runs (60), triples (11), extra-base hits (43) and total bases (171). That offensive production is for real, as he's a switch-hitter with solid pop and above-average speed.

In Bryant, Baez and Alcantara, the Cubs have three potential All-Stars just a phone call away from Wrigley Field. Beyond them, the Iowa lineup also features two other players who could fill roles in the big leagues.

A football star at Villanova, speedy Matt Szczur profiles as a useful fourth outfielder. Logan Watkins already has played everywhere but catcher and pitcher for the I-Cubs, and he can fill a utility role in Chicago.

Because the Cubs aren't in contention, there's less incentive to promote their top prospects from Iowa and get them started on the road to arbitration and free agency. As a result, Bryant, Baez and Alcantara could spend the entire season in Iowa. Once they get the call to Chicago, the Cubs should find it easier to score runs and return to contention.