The NFL’s pre-draft circus hits the road this week with coaches and scouts visiting campuses across the country to see players who missed the Indianapolis combine or who vow to improve results from there during on-campus Pro Days.

Or, as some scouts refer to these events: Pro Daze.

They know to beware of the credibility of any alleged improvement at a Pro Day compared to the combine. In this case, the numbers can lie, and usually do in the times for popular running events.

Once the so-called underwear Olympics leaves the confines of Indianapolis’ Lucas Oil Stadium, scouts are wary of results turned in from campus workouts.

These concerns no longer focus on those old tricks used to enhance a player’s data, such as the 40-yard dash that is only 38 yards long or the 225-pound bench press with 215 pounds as well as various chicanery measuring the vertical jumps.

“Teams became wise to those tricks years ago,” said Jon Kingdon, who traveled the scouting trail 30 years for the Oakland/Los Angeles Raiders. “To make sure, we actually measured the 40 yards sometimes.”

But tricks aren’t the only difference. The elements, surface and timing method are exactly the same for each player at Indianapolis. That is not so for Pro-Day workouts on each campus.

Even if the elements were the same, the difference in methods results in what seems to be a significant improvement in the timed events, especially the popular 40-yard dash (and the 10-, 20-yard splits). While the combine announces so-called electronic times, Pro-Day workouts are almost all timed by hand-held stopwatches. One notable exception will be Oklahoma University (March 11), which will use the same Zybek Sports timing equipment that was at Indianapolis. The Colorado schools may also use Zybek, which is based in that state.

The inherent disparity between hand held (HH) and electronic times (ET) is demonstrated during the combine itself. All 258 players who ran were timed in multiple ways, include HH and ET. In a result that conforms with empirical data from almost a million examples by Zybek over the last eight years, the hand-held times were, on average, almost .07 seconds faster than the announced electronic times.

In fact, 241 of the 258 runners had faster HH times than the ET times that were announced. Six were about the same and only 11 HH times were slower than ET, with 10 of those only by .01 second.

The difference would be even wider — and is in other combines — but Minnesota Vikings scout Terrance Gray is probably the best in the business with a stopwatch. At the combine, Gray starts so-called electronic time from his spot seven yards away from the runner. Data from HH times outside the combine show discrepancies that often average .175 seconds at a given event, with the largest gaps the result of watches started and stopped at the finish line.

With more and more Pro Days held on a version of the Field Turf product used at the combine, another variable is disappearing. When Pro Days were held on a variety of surfaces, Ron Wolf had a formula to translate them into a single reference number for consistency.

Wolf is the long-time personnel virtuoso and former Green Bay Packers general manager headed to the Pro Football Hall of Fame this year for many reasons, including his attention to detail. When evaluating a player’s various data in days of widely differing Pro-Day elements, Wolf added .12 seconds to 40-yard times taken on a track surface and .08 for those run on AstroTurf.

Those are just a couple of examples of how he reconciled disparate situations to align data that equated to what a player would do on his team’s surface, which was natural grass when he was with the Packers and Oakland Raiders.

Now Field Turf, or something similar, is at almost all Pro Days and the 38-yard scams are just another quaint story from the past. Still, players who vow to improve that 40-yard time announced at the combine, must to do so by at least .07 seconds before it can be considered as an improvement.

As Pro Days begin this week, here is a guideline for every player who ran at Indianapolis and the HH target time (.07 faster) he must get just to equal his combine time, let alone claim improvement.

Results are listed in order of fasted announced times at the Indianapolis combine:

Player, Position, College, Combine, Target

J.J. Nelson, WR, UAB, 4.28, 4.21

*Trae Waynes, CB, Michigan State, 4.31, 4.24

Phillip Dorsett, WR, Miami, 4.33, 4.26

Chris Conley, WR, Georgia, 4.35, 4.28

Kevin White, WR, West Virginia, 4.35, 4.28

Justin Cox, CB, Mississippi State, 4.36, 4.29

*Ronald Darby, CB, Florida State, 4.38, 4.31

Tyler Lockett, WR, Kansas State, 4.40, 4.33

Tre McBride, WR, William & Mary, 4.41, 4.34

*Nelson Agholor, WR, Southern Cal, 4.42, 4.35

Kenny Bell, WR, Nebraska, 4.42, 4.35

*Amari Cooper, WR, Alabama, 4.42, 4.35

Jeremy Langford, RB, Michigan State, 4.42, 4.35

Devin Smith, WR, Ohio State, 4.42, 4.35

Mario Alford, WR, West Virginia, 4.43, 4.36

Sammie Coates, WR, Auburn, 4.43, 4.36

Charles Gaines, CB, Louisville, 4.44, 4.37

Antwan Goodley, WR, Baylor, 4.44, 4.37

Doran Grant, CB, Ohio State, 4.44, 4.37

Craig Mager, CB, Texas State, 4.44, 4.37

Josh Shaw, CB, Southern Cal, 4.44, 4.37

*Jaelen Strong, WR, Arizona State, 4.44, 4.37

DeAndrew White, WR, Alabama, 4.44, 4.37

DeVante Parker, WR, Louisville, 4.45, 4.38

Eric Rowe, CB, Utah, 4.45, 4.38

DJoun Smith, CB, Florida Atlantic, 4.45, 4.38

*Stefon Diggs, WR, Maryland, 4.46, 4.39

Senquez Golson, CB, Mississippi, 4.46, 4.39

Damarious Randall, FS, Arizona State, 4.46, 4.39

Darren Waller, WR, Georgia Tech, 4.46, 4.39

*Jalen Collins, CB, LSU, 4.48, 4.41

Karlos Williams, RB, Florida State, 4.48, 4.41

*Dorial Green-Beckham, WR, Oklahoma, 4.49, 4.42

Steven Nelson, CB, Oregon State, 4.49, 4.42

*Trey Williams, RB, Texas AM, 4.49, 4.42

*Lorenzo Doss, CB, Tulane, 4.50, 4.43

David Johnson, RB, Northern Iowa, 4.50, 4.43

Damian Swann, CB, Georgia, 4.50, 4.43

*Alex Carter, CB, Stanford, 4.51, 4.44

Kaelin Clay, WR, Utah, 4.51, 4.44

Titus Davis, WR, Central Michigan, 4.51, 4.44

Deon Long, WR, Maryland, 4.51, 4.44

Bobby McCain, CB, Memphis, 4.51, 4.44

*Melvin Gordon, RB, Wisconsin, 4.52, 4.45

Kevin Johnson, CB, Wake Forest, 4.52, 4.45

Marcus Mariota, QB, Oregon, 4.52, 4.45

*Javorius Allen, RB, Southern Cal, 4.53, 4.46

Cameron Artis-Payne, RB, Auburn, 4.53, 4.46

Vic Beasley, OLB, Clemson, 4.53, 4.46

Justin Coleman, CB, Tennessee, 4.53, 4.46

*Landon Collins, SS, Alabama, 4.53, 4.46

Rashad Greene, WR, Florida State, 4.53, 4.46

*Marcus Peters, CB, Washington, 4.53, 4.46

Jaquiski Tartt, SS, Samford, 4.53, 4.46

DaRon Brown, WR, Northern Illinois, 4.54, 4.47

*Duke Johnson, RB, Miami, 4.54, 4.47

Nick Marshall, CB, Auburn, 4.54, 4.47

Keith Mumphery, WR, Michigan State, 4.54, 4.47

*Kwon Alexander, OLB, LSU, 4.55, 4.48

Clayton Geathers, SS, Central Florida, 4.55, 4.48

Troy Hill, CB, Oregon, 4.55, 4.48

Ty Montgomery, WR, Stanford, 4.55, 4.48

Adrian Amos, FS, Penn State, 4.56, 4.49

Stephone Anthony, ILB, Clemson, 4.56, 4.49

Jamison Crowder, WR, Duke, 4.56, 4.49

Quandre Diggs, CB, Texas, 4.56, 4.49

Alvin Dupree, DE, Kentucky, 4.56, 4.49

Justin Hardy, WR, East Carolina, 4.56, 4.49

*James Sample, SS, Louisville, 4.56, 4.49

*Jay Ajayi, RB, Boise State, 4.57, 4.50

*B.J. Catalon, RB, TCU, 4.57, 4.50

Devante Davis, WR, UNLV, 4.57, 4.50

*Danielle Hunter, DE, LSU, 4.57, 4.50

Kyshoen Jarrett, SS, Virginia Tech, 4.57, 4.50

Quinten Rollins, CB, Miami (Ohio), 4.57, 4.50

Blake Sims, QB, Alabama, 4.57, 4.50

*P.J. Williams, CB, Florida State, 4.57, 4.50

Michael Dyer, RB, Louisville, 4.58, 4.51

Dezmin Lewis, WR, Central Arkansas, 4.58, 4.51

Dean Marlowe, FS, James Madison, 4.58, 4.51

MyCole Pruitt, TE, Southern Illinois, 4.58, 4.51

Julian Wilson, CB, Oklahoma, 4.58, 4.51

Ben Heeney, ILB, Kansas, 4.59, 4.52

Jermaine Whitehead, FS, Auburn, 4.59, 4.52

Ameer Abdullah, RB, Nebraska, 4.60, 4.53

*Dante Fowler, OLB, Florida, 4.60, 4.53

Bryce Hager, ILB, Baylor, 4.60, 4.53

Rannell Hall, WR, Central Florida, 4.60, 4.53

*Eli Harold, OLB, Virginia, 4.60, 4.53

Cody Prewitt, FS, Mississippi, 4.60, 4.53

Tye Smith, CB, Towson, 4.60, 4.53

Zach Zenner, FB, South Dakota State, 4.60, 4.53

*Mike Davis, RB, South Carolina, 4.61, 4.54

*Matt Jones, RB, Florida, 4.61, 4.54

Eric Kendricks, ILB, UCLA, 4.61, 4.54

Tony Lippett, WR, Michigan State, 4.61, 4.54

Marcus Murphy, RB, Missouri, 4.61, 4.54

Garry Peters, CB, Clemson, 4.61, 4.54

Edmond Robinson, OLB, Newberry, 4.61, 4.54

*T.J. Yeldon, RB, Alabama, 4.61, 4.54

Malcolm Brown, RB, Texas, 4.62, 4.55

Donald Celiscar, CB, Western Michigan, 4.62, 4.55

John Crockett, RB, North Dakota State, 4.62, 4.55

*DaVaris Daniels, WR, Notre Dame, 4.62, 4.55

Owamagbe Odighizuwa, DE, UCLA, 4.62, 4.55

Ross Scheuerman, WR, Lafayette, 4.62, 4.55

*Durrell Eskridge, FS, Syracuse, 4.63, 4.56

Cody Fajardo, QB, Nevada, 4.63, 4.56

*Braylon Heard, RB, Kentucky, 4.63, 4.56

Brett Hundley, QB, UCLA, 4.63, 4.56

Christion Jones, WR, Alabama, 4.63, 4.56

Tevin McDonald, FS, Eastern Washington, 4.63, 4.56

Kevin White, CB, TCU, 4.63, 4.56

*Jacoby Glenn, CB, Central Florida, 4.64, 4.57

*Randy Gregory, DE, Nebraska, 4.64, 4.57

Josh Harper, WR, Fresno State, 4.64, 4.57

*Shaq Thompson, OLB, Washington, 4.64, 4.57

Kurtis Drummond, FS, Michigan State, 4.65, 4.58

Donatella Luckett, WR, Harding, 4.65, 4.58

Thomas Rawls, RB, Central Michigan, 4.65, 4.58

Jordan Richards, SS, Stanford, 4.65, 4.58

Jake Ryan, OLB, Michigan, 4.65, 4.58

Wes Saxton, TE, South Alabama, 4.65, 4.58

*Benardrick McKinney, ILB, Mississippi State, 4.66, 4.59

Vince Mayle, WR, Washington State, 4.67, 4.60

Jordan Hicks, OLB, Texas, 4.68, 4.61

Zack Hodges, OLB, Harvard, 4.68, 4.61

Mike Hull, OLB, Penn State, 4.68, 4.61

Ezell Ruffin, WR, San Diego State, 4.68, 4.61

Ladarius Gunter, CB, Miami, 4.69, 4.62

*Devin Funchess, WR, Michigan, 4.70, 4.63

Gus Johnson, RB, Stephen F. Austin, 4.70, 4.63

*Josh Robinson, RB, Mississippi State, 4.70, 4.63

Brandon Bridge, QB, South Alabama, 4.72, 4.65

Obum Gwacham, DE, Oregon State, 4.72, 4.65

Anthony Jefferson, SS, UCLA, 4.72, 4.65

Alani Fua, OLB, BYU, 4.73, 4.66

Michael Burton, FB, Rutgers, 4.74, 4.67

Xzavier Dickson, OLB, Alabama, 4.74, 4.67

Preston Smith, DE, Mississippi State, 4.74, 4.67

Ryan Russell, DE, Purdue, 4.75, 4.68

Kyle Emanuel, OLB, North Dakota State, 4.77, 4.70

Damien Wilson, ILB, Minnesota, 4.77, 4.70

Ramik Wilson, ILB, Georgia, 4.77, 4.70

Denzel Perryman, ILB, Miami, 4.78, 4.71

Hayes Pullard, ILB, Southern Cal, 4.78, 4.71

*Maxx Williams, TE, Minnesota, 4.78, 4.71

Anthony Chickillo, DE, Miami, 4.79, 4.72

Frank Clark, DE, Michigan, 4.79, 4.72

Clive Walford, TE, Miami, 4.79, 4.72

Tavaris Barnes, DE, Clemson, 4.80, 4.73

Blake Bell, TE, Oklahoma, 4.80, 4.73

Jahwan Edwards, RB, Ball State, 4.80, 4.73

Dee Hart, RB, Colorado State, 4.80, 4.73

Nate Orchard, DE, Utah, 4.80, 4.73

Bryan Bennett, QB, Southeast Louisiana, 4.81, 4.74

Geneo Grissom, OLB, Oklahoma, 4.81, 4.74

*Chris Hackett, FS, TCU, 4.81, 4.74

Zach Wagenmann, DE, Montana, 4.82, 4.75

Amarlo Herrera, ILB, Georgia, 4.83, 4.76

Kenny Hilliard, RB, LSU, 4.83, 4.76

*Jesse James, TE, Penn State, 4.83, 4.76

ZaDarius Smith, DE, Kentucky, 4.83, 4.76

*Max Valles, OLB, Virginia, 4.83, 4.76

*Mario Edwards, DE, Florida State, 4.84, 4.77

*Jean Sifrin, TE, Massachusetts, 4.84, 4.77

Lorenzo Mauldin, OLB, Louisville, 4.85, 4.78

*Xavier Cooper, DT, Washington State, 4.86, 4.79

Gerald Christian, TE, Louisville, 4.87, 4.80

Bryce Petty, QB, Baylor, 4.87, 4.80

Martin Ifedi, DE, Memphis, 4.88, 4.81

Martrell Spaight, OLB, Arkansas, 4.88, 4.81

Markus Golden, OLB, Missouri, 4.90, 4.83

Joe Cardona, LS, Navy, 4.91, 4.84

J.R. Tavai, OLB, Southern Cal, 4.91, 4.84

Lynden Trail, DE, Norfolk State, 4.91, 4.84

Paul Dawson, ILB, TCU, 4.93, 4.86

Trey Flowers, DE, Arkansas, 4.93, 4.86

Nick OLeary, TE, Florida State, 4.93, 4.86

Shane Carden, QB, East Carolina, 4.94, 4.87

Jalston Fowler, FB, Alabama, 4.94, 4.87

Aaron Davis, OLB, Colorado State, 4.95, 4.88

Taiwan Jones, ILB, Michigan State, 4.95, 4.88

Louis Trinca-Pasat, DT, Iowa, 4.96, 4.89

Henry Anderson, DE, Stanford, 4.97, 4.90

Ryan Delaire, DE, Towson, 4.97, 4.90

*Leonard Williams, DT, Southern Cal, 4.97, 4.90

*Jameis Winston, QB, Florida State, 4.97, 4.90

Cameron Clear, OT, Texas A&M, 4.98, 4.91

Ali Marpet, OG, Hobart, 4.98, 4.91

Eric Tomlinson, TE, Texas-El Paso, 4.98, 4.91

Derrick Lott, DT, Chattanooga, 4.99, 4.92

Jerry Lovelocke, QB, Prairie View A&M, 4.99, 4.92

Tony Washington, OLB, Oregon, 4.99, 4.92

*Darius Philon, DT, Arkansas, 5.00, 4.93

Corey Crawford, DE, Clemson, 5.01, 4.94

Jake Fisher, OT, Oregon, 5.01, 4.94

Angelo Blackson, DT, Auburn, 5.02, 4.95

Joey Iosefa, FB, Hawaii, 5.02, 4.95

*Rakeem Nunez-Roches, DT, Southern Miss, 5.02, 4.95

Anthony Boone, QB, Duke, 5.03, 4.96

Nick Boyle, TE, Delaware, 5.04, 4.97

Laurence Gibson, OT, Virginia Tech, 5.04, 4.97

*Malcom Brown, DT, Texas, 5.05, 4.98

Brandon Scherff, OT, Iowa, 5.05, 4.98

B.J. Dubose, DE, Louisville, 5.06, 4.99

Grady Jarrett, DT, Clemson, 5.06, 4.99

Carl Davis, DT, Iowa, 5.07, 5.00

Gabe Wright, DT, Auburn, 5.07, 5.00

Terry Poole, OT, San Diego State, 5.09, 5.02

*Arik Armstead, DT, Oregon, 5.10, 5.03

La’el Collins, OT, LSU, 5.12, 5.05

*D.J. Humphries, OT, Florida, 5.12, 5.05

Deon Simon, DT, Northwestern State (La.), 5.12, 5.05

T.J. Clemmings, OT, Pittsburgh, 5.14, 5.07

Sean Mannion, QB, Oregon State, 5.14, 5.07

Mitch Morse, OG, Missouri, 5.14, 5.07

Cameron Erving, C, Florida State, 5.15, 5.08

Chaz Green, OT, Florida, 5.16, 5.09

Leon Orr, DT, Florida, 5.16, 5.09

Bobby Richardson, DT, Indiana, 5.16, 5.09

*Jordan Phillips, DT, Oklahoma, 5.17, 5.10

Tyeler Davison, DT, Fresno State, 5.18, 5.11

*Andrus Peat, OT, Stanford, 5.18, 5.11

Takoby Cofield, OT, Duke, 5.19, 5.12

Jarvis Harrison, OG, Texas A&M, 5.19, 5.12

J.T. Surratt, DT, South Carolina, 5.19, 5.12

Mark Glowinski, OG, West Virginia, 5.20, 5.13

*Ellis McCarthy, DT, UCLA, 5.21, 5.14

Jamil Douglas, OG, Arizona State, 5.25, 5.18

B.J. Finney, C, Kansas State, 5.25, 5.18

Leterrius Walton, DT, Central Michigan, 5.25, 5.18

Rob Crisp, OT, North Carolina State, 5.26, 5.19

Donovan Smith, OT, Penn State, 5.27, 5.20

Trenton Brown, OT, Florida, 5.29, 5.22

Reese Dismukes, C, Auburn, 5.31, 5.24

Andrew Donnal, OT, Iowa, 5.31, 5.24

*Ereck Flowers, OT, Miami, 5.31, 5.24

*Jeremiah Poutasi, OG, Utah, 5.32, 5.25

Jon Feliciano, OG, Miami, 5.33, 5.26

John Miller, OG, Louisville, 5.33, 5.26

Laken Tomlinson, OG, Duke, 5.33, 5.26

Daryl Williams, OT, Oklahoma, 5.34, 5.27

Ty Sambrailo, OT, Colorado State, 5.36, 5.29

David Parry, DT, Stanford, 5.38, 5.31

Austin Shepherd, OT, Alabama, 5.39, 5.32

Robert Myers, OG, Tennessee State, 5.44, 5.37

Rob Havenstein, OT, Wisconsin, 5.46, 5.39

Andy Gallik, C, Boston College, 5.50, 5.43

Darrian Miller, OT, Kentucky, 5.51, 5.44

Tre Jackson, OG, Florida State, 5.52, 5.45

Josue Matias, OG, Florida State, 5.52, 5.45

Joey Mbu, DT, Houston, 5.54, 5.47

Tayo Fabuluje, OG, TCU, 5.55, 5.48

Al Bond, OG, Memphis, 5.57, 5.50

Brett Boyko, OG, UNLV, 5.60, 5.53

Danny Shelton, DT, Washington, 5.64, 5.57

Adam Shead, OG, Oklahoma, 5.74, 5.67