A year ago, nine rookie running backs rushed for at least 500 yards. Based on recent history, what can we expect from those backs in 2015, their second seasons in the league?

The odds of them putting up better or at least comparable rushing numbers in their second season appear to be about 50-50. Since 2000, 61 other running backs have rushed for at least 500 yards in their rookie seasons. About half of those players (30) have come back and rushed for either more yardage in year 2 or declined minimally (10 percent or less).

The other 31 players have declined by 18 percent or more, with close to half (14) experiencing at least a 50 percent decline. Based on that, it looks reasonable to suppose that 4-5 of those rookie will post similar or better numbers in 2015, while the others will decline -- and a couple of those guys dramatically.

The last 61 rookie runners over 500 yards, sorted by percent increase or decrease in year 2, are presented below.

ROOKIE RUNNING BACKS, YEAR 2, 2000-2014
YearPlayerTeamRuYds (1)RuYds (2)% change
2005Frank GoreS.F.6081695179%
2001Travis HenryBuff.729143897%
2001Michael BennettMinn.682129690%
2009LeSean McCoy Phil.637108070%
2008Chris JohnsonTenn.1228200663%
2010Ryan MathewsS.D.678109161%
2013LeVeon BellPitt.860136158%
2004Steven JacksonSt.L.673104655%
2002T.J. DuckettAtl.50777954%
2006DeAngelo WilliamsCar.50171743%
2009Shonn Greene NYJ54076642%
2001LaDainian TomlinsonS.D.1236168336%
2008Jonathan StewartCar.836113336%
2001Kevan BarlowS.F.51267532%
2007Adrian PetersonMinn.1341176031%
2005Marion BarberDall.53865422%
2004Julius JonesDall.81999321%
2003Domanick DavisHou.1031118815%
2006Laurence MaroneyN.E.74583512%
2005Ronnie BrownMia.907100811%
2002Clinton PortisDen.150815916%
2006Reggie BushN.O.5655813%
2013Andre Ellington Ariz.6526601%
2006Joseph AddaiInd.10811072-1%
2013Giovani BernardCin.695680-2%
2006Jerious NorwoodAtl.633613-3%
2013Eddie LacyG.B.11781139-3%
2003Onterrio SmithMinn.579544-6%
2007Marshawn LynchBuff.11151036-7%
2000Ron DayneNYG770690-10%
2009Knowshon Moreno Den.947779-18%
2012Bernard PierceBalt.532436-18%
2006Maurice Jones-DrewJac.941768-18%
2012Alfred MorrisWash.16131275-21%
2010LeGarrette BlountTenn.1007781-22%
2008Kevin SmithDet.976747-23%
2008Matt ForteChi.1238929-25%
2011DeMarco MurrayDall.897663-26%
2010Jahvid BestDet.555390-30%
2005Cadillac WilliamsT.B.1178798-32%
2002William GreenClev.887559-37%
2001Anthony ThomasChi.1183721-39%
2004Kevin JonesDet.1133664-41%
2011Daniel ThomasMia.581325-44%
2012Bryce BrownPhil.564314-44%
2006Leon WashingtonNYJ650353-46%
2009Beanie Wells Ariz.793397-50%
2012Trent RichardsonClev.950458-52%
2000Mike AndersonDen.1487678-54%
2005Samkon GadoK.C.582210-64%
2008Steve SlatonHou.1282437-66%
2012Doug MartinT.B.1454456-69%
2013Montee BallDen.559172-69%
2013Zac Stacy St.L.973293-70%
2001James JacksonClev.55454-90%
2012Vick BallardInd.81463-92%
2002Jonathan WellsHou.52914-97%
2000Travis PrenticeClev.51213-97%
2011Roy HeluWash.6402-100%
2000Jamal LewisBalt.13640-100%
2001Correll BuckhalterPhil.5860-100%
2014Jeremy HillCin.1124??
2014Tre MasonSt.L.765??
2014Andre WilliamsNYG721??
2014Terrance WestClev.673??
2014Isaiah CrowellClev.607??
2014Branden OliverS.D.582??
2014Bishop SankeyTenn.569??
2014Jerick McKinnonMinn.538??
2014Alfred BlueHou.528??

--Andy Richardson