The PGA Tour is four events into its restarted season, and two trends have emerged.

First, extremely low scores have been needed to win.

Daniel Berger beat Collin Morikawa in a playoff in the Charles Schwab Challenge after each player finished 72 holes at 15 under. The following week Webb Simpson won the RBC Heritage by reaching 22 under par. Dustin Johnson won the Travelers Championship at 19 under, and Bryson DeChambeau won the Rocket Mortgage Classic with a winning score of 23 under par.

Second, driving distance and effectiveness off the tee have been especially important in achieving those low scores.

With that in mind, here is a list of the players ranked in the top 10 on the PGA Tour in strokes gained off the tee and the drivers they play. Strokes gained measures how many strokes better or worse any player is in each round versus the field average.

(David Dusek/Golfweek)

Driver: Ping G410 LST (9 degrees), with Project X HZRDUS Black Hand Crafted 6.5 X shaft

Scottie Scheffler's Ping G400 LST driver

(Raymond Carlin III/USA TODAY Sports)

Driver: Ping G400 LST (9 degrees), with Fujikura ATMOS Black shaft

Xander Schauffele's Callaway Mavrik Sub Zero driver

(Bill Streicher/USA TODAY Sports)

Driver: Callaway Mavrik Sub Zero (9 degrees), with Graphite Design Tour AD BB 7X shaft

Jason Kokrak's TaylorMade SIM driver

(Ron Jenkins/Getty Images)

Driver: TaylorMade SIM (10.5 degrees), with Project X EvenFlow Riptide S shaft

Jon Rahm's TaylorMade SIM driver

(Raymond Carlin III/USA TODAY Sports)

Driver: TaylorMade SIM (10.5 degrees), with Aldila Tour Green 75 TX shaft

Bubba Watson's Ping G410 Plus driver.

(David Dusek/Golfweek)

Driver: Ping G410 Plus (9 degrees set at 6.8), with Grafalloy Bi-Matrix X shaft

Jhonattan Vegas's TaylorMade SIM driver.

(Maddie Meyer/Getty Images)

Driver: TaylorMade SIM (9 degrees), with Motore X F1 7X shaft

Rory McIlroy's TaylorMade SIM driver

(David Dusek/Golfweek)

Driver: TaylorMade SIM (10.5 degrees), with Mitsubishi Kuro Kage XTS 70 X shaft

Sergio Garcia's Ping G410 LST driver

(Raymond Carlin III/USA TODAY Sports)

Driver: Ping G410 LST (9 degrees), with Mitsubishi Tensei CK Blue 80 TX shaft

Bryson DeChambeau's Cobra King LTD Black driver

(Brian Spurlock/USA TODAY Sports)

Driver: Cobra King Speedzone (5.5 degrees), with LAGP BAD prototype 60X shaft

Cameron Champ's Ping G410 LST driver

(David Dusek/Golfweek)

Driver: Ping G410 LST (9 degrees), with Project X HZRDUS Smoke Green 70 TX shaft