McKercher Breakout Watch: Can He Crack the GDS DEF Top 7?

Colby McKercher averaged 95.6 GDS across his full 2025 season. That number does not tell you the real story. Strip the season in half and the picture changes completely. Pre-bye, he averaged 71.9 GDS across 11 games in a variety of roles. Post-bye, after a move to half-back, he averaged 117.3 GDS across 12 games. That is a 63% jump. And now there are reports of a midfield push for 2026. The third-year Roo, who turns 21 in April, is entering the season where breakouts happen.

The 2025 Split: Role Change, Not Hot Streak

The first thing to check with any split season is whether the improvement is role-driven or form-driven. If the TOG, disposal volume, and kick count all shift structurally, it is a role change. If just the scoring jumps while everything else stays flat, it is more likely a hot streak. McKercher's data leaves no room for debate.

Split	Games	GDS Avg	Disposals	Kicks	Marks	TOG
Pre-bye (R1-R11)	11	71.9	16.1	9.4	3.2	77.8
Post-bye (R13-R24)	12	117.3	29.6	19.9	3.6	85.9
Difference		+45.4	+13.5	+10.5	+0.4	+8.1

Every key indicator shifted. His TOG jumped from 77.8 to 85.9, meaning he was spending more time on the ground. His disposals went from 16.1 to 29.6, nearly doubling. Most importantly, his kicks jumped from 9.4 to 19.9 per game. Kicks are the single most important stat for GDS DEF scoring because they carry more weight than handballs. A defender who kicks 20 times a game is a GDS machine. McKercher became exactly that after the bye.

His CBA share stayed at zero post-bye, confirming he was playing a pure half-back role, not drifting into the midfield. All of his GDS output came from transition: running off half-back, taking intercept possessions, and using his foot skills to move the ball. This is the profile that thrives in a reduced-stoppage game, which is exactly the direction the 2026 rules are pushing.

Where McKercher Sits Against the GDS DEF Top 10

The GDS DEF position is deep. The top 7 (the squad cutoff) averaged between 113.0 and 135.4 GDS in 2025. Here is where McKercher slots in.

Rank	Player	GDS Avg	Disposals	Marks	Kicks
1	Nasiah Wanganeen-Milera	135.4	29.9	5.3	22.3
2	Lachie Whitfield	125.6	28.3	7.2	19.0
3	Connor Rozee	125.3	27.5	4.9	18.0
4	Dayne Zorko	124.4	25.8	6.8	20.8
5	Jack Sinclair	121.8	27.0	4.8	19.4
6	Lachie Ash	120.0	27.9	6.3	18.4
7	Bailey Dale	113.0	27.0	4.7	19.7
	McKercher (post-bye)	117.3	29.6	3.6	19.9
	McKercher (full season)	95.6	23.1	3.4	14.9

McKercher's full-season average of 95.6 puts him well outside the top 10. But his post-bye average of 117.3 would slot him as DEF6, above Bailey Dale (113.0) and just below Lachie Ash (120.0). His 29.6 disposals and 19.9 kicks per game post-bye would be the second highest of any DEF behind Nasiah Wanganeen-Milera. The question is whether 2026 looks like his pre-bye or his post-bye. The evidence strongly suggests the post-bye version is the real one, because it was driven by a structural role change, not variance.

The Midfield Push: What It Means for GDS

Reports out of North Melbourne's preseason indicate McKercher is being given more midfield time in 2026. If this holds, it changes the equation entirely. His GDS position tag for 2026 is DEF, which means any midfield scoring output gets counted against the shallower DEF pool. A DEF who attends even a small percentage of CBAs gets mid-like scoring from a position where the top-10 threshold is lower.

McKercher's 2025 CBAs were essentially zero post-bye. If he picks up even 5 to 10 CBAs per game in 2026, his disposal and tackle numbers should lift further. The pre-bye data from early 2025 is less relevant because he was being used in different roles. The post-bye half-back role is the baseline. Midfield minutes on top of that is pure upside.

The Age Curve: Third-Year Breakout Territory

McKercher enters 2026 at age 20 turning 21. This is his third season on an AFL list. History tells us the third year is where young GDS defenders tend to take the leap. Here is how two recent DEF breakouts tracked.

Player	Age 19-20 GDS	Age 21-22 GDS	Breakout Jump
Colby McKercher	98.9 (2024)	95.6* (2025)	117.3 post-bye
Nasiah Wanganeen-Milera	N/A (no data)	118.5 (2024)	+16.9 to 135.4
Lachie Ash	N/A (no data)	89.4 (2024)	+30.6 to 120.0

Nasiah Wanganeen-Milera went from 118.5 GDS in 2024 (age 21) to 135.4 in 2025 (age 22), a 16.9 point jump that made him the clear DEF1 in GDS. Lachie Ash made an even bigger leap, going from 89.4 in 2024 to 120.0 in 2025, a 30.6 point improvement that saw him crack the top 7. Both breakouts were role-driven: NWM's kick volume jumped from 19.8 to 22.3, while Ash's went from 12.8 to 18.4.

McKercher's post-bye kick volume of 19.9 is already comparable to NWM's pre-breakout level. His disposal volume of 29.6 post-bye is elite for any defender. If he can sustain that output across a full season, a 115 to 120+ GDS average is realistic. That puts him firmly inside the top 7 and on the doorstep of the top 5.

GDS Verdict: McKercher for 2026

The data points clearly toward a breakout. The 2025 post-bye split is role-driven, not a hot streak. The kick and disposal volume is already elite. The age curve lines up. And the midfield push adds upside that is not yet priced into his card value.

McKercher's full-season average of 95.6 GDS in 2025 is what the market sees. His post-bye average of 117.3 is what the data says he actually is. If the half-back role holds and midfield minutes are added, a full-season average of 115+ is the reasonable projection. That would make him a top-7 DEF and a genuine candidate for the top 5 if everything clicks.

The call: get his card before the market catches up. The role change was real, the age curve supports it, and the preseason reports only strengthen the case. McKercher is the kind of underpriced asset that wins GDS seasons. We rate McKercher as a 60% player for 2026, projecting him as a regular starter most weeks with top-5 upside if the midfield role materialises.