Identification Of Position-Specfic Combine Test Score Thresholds For Drafted And Non-Drafted Defensive Players Entering The National Football League

Abstract

The National Football League (NFL) Combine (COM) is a test battery designed to identify the collegiate players that could be successfully drafted into the NFL. Although another study has investigated the prediction of draft status from multiple COM test scores, the specific identification of threshold values from each COM test score that distinguishes subgroups of players with a greater or a lesser chance of being drafted is unknown. The purpose of this study was to identify, for each defensive position, the specific COM tests and their threshold values that contribute to an increased or decreased likelihood of being drafted. The COM data for 758 defensive players (average round drafted 4.0 ± 1.9), 127 defensive tackles (DT), 155 defensive ends (DE), 81 inside linebackers (ILB), 125 outside linebackers (OLB), 138 cornerbacks (CB) and 132 safeties (S) from 1999 to 2008 was gathered from www.nfldraftscout.com, a source of COM data in other investigations. Only players who had a complete set of the COM variables: height (HT), weight (WT), body mass index (body weight/height2) (BMI), 40-(FD), 20-(TW) and 10-(TE) yard dash, 3-cone drill (3C), pro agility (PA), vertical jump (VJ), broad jump (BJ), and 225lb bench press (BP) repetitions-to-failure were included in the study. Signal detection analysis (SDA) (sensitivity & specificity = 50%) identified the significant COM test subgroups and decision tree for each position. A decision tree with DE is shown in Figure 1. The SDA yielded 4 subgroups of varying percentages of drafted players for all positions. However, ILB and CB only had 3 subgroups due to smaller undrafted sample sizes in those positions. The subgroup with the highest number of drafted players for each position is as follows, for DT: WT > 299lbs and a TE < 1.85s (83.1% drafted), DE: FD < 4.88s and a WT > 254lbs (94.4% drafted), ILB: TW < 2.81s and a BP > 20 repetitions (85% drafted), OLB: TE < 1.68s and a PA < 4.36s (88.2% drafted), CB: FD < 4.59s and a PA < 4.33s (91.9% drafted) and S: FD < 4.59s and a TW < 2.65s (86.0% drafted). The identified COM tests for each position matched the perceived on field demands of that position. Speed coupled with lateral quickness or acceleration was important for CB and S who cover offensive backs and receivers in passing routes. Speed or acceleration along with body size was important for the DT and DE who must elude offensive linemen, stop the run and rush the quarterback (QB). Acceleration and strength were important for ILB who play a quick and physically demanding position, while acceleration and lateral quickness were important for OLB who not only cover backs and receivers in passing routes but also rush the QB. The present identification of position-specific COM test score thresholds may provide useful training goals that, if reached, could increase the likelihood of being drafted.