Introduction

This article will lay out some data behind Spectrum, what it is and what makes it valuable as a DFS Tool and betting tool for identifying "true" performance skill and undervalued players. First let's take this article from the approach of the current state Spectrum Data which is all of the Strokes Gained categories. Spectrum has the opportunity of revising nearly every statistic, many of which are in the works and will be in production soon, but for brevity let's focus on the Strokes Gained categories. Before we dive into it, let's do a refresher on Strokes Gained.

Strokes Gained Basics

Strokes Gained is a broadly used term in the PGA gambling space, but it refers to any of the categories of stats as shown below. SG:Total is essentially the scoring average relative to the field (in reverse), for example if a player shoots -2 on a round when the field's scoring average was -1, then their SG:Total would be +1. Mark Broadie (the inventor of Strokes Gained) took this breakout a step further with the addition of SG:Putting and SG:T2G. Basically this allowed PGA Tour fans to see how a player performed in their SG:Total value, broken out between Putting and everything else Tee-to-green. Since then, the PGA Tour further broke out SG:T2G but separating SG:OTT (Off the tee), SG:APP (Approach) and SG:ARG (Around the green). This is where the first issue arose in Strokes Gained metrics and the way they are used today.

Strokes Gained Math

The math for Strokes Gained is quite simple, however. Each shot has a PGA Tour baseline. Let's use putting for our first example, referencing the SG:PUTT chart from below:

So let's make an example, the player hit their approach shot to 30 feet. They have 2.00 stroke expectation here. So for their next shot, they are a bit too aggressive and run it 5 ft by the hole. The expected strokes gained from 5 ft. is 1.15, so for this single 30 ft. putt, the player's SG:PUTT calculation is: 2.0 (expectation from 30ft.) - 1.15 (expectation from 5 ft.) - 1 (the stroke they took) = -0.15

So for this example, the player lost 0.15 strokes putting. They then make their 5 ft. putt, which is then: 1.15 (expectation from 5 ft.) - 0 (ball is holed, no expectation remaining) - 1 ( the stroke they took) = +0.15

So on this 30 ft. putt the player lost 0.15 strokes on their first putt then gained 0.15 on their second putt, exactly matching the 2 stroke expectation from 30 ft. leading to a SG:PUTT metric of 0.00.

The same math applies to other SG categories, for example SG:OTT. The player begins on the tee for a 450 yard hole with the expectation of 4.1 strokes to complete the hole. The player then hits a 300 yard drive into the fairway and has 150 yards remaining. The benchmark from 150 yards is 2.9 strokes, so the math is as follows for SG:OTT on this drive: 4.1 (benchmark from the tee box) - 2.9 (benchmark for 150 yards remaining) - 1 (the stroke they took) = +0.2

So this player gained 0.2 strokes OTT on this single tee shot.