This is confidence, not cockiness. We've put enormous thought and energy into getting this right, and we're building on lots of work at other tokamaks (including many tokamaks where our own founders and other employees worked).
And we have a lot of leeway in reaching our initial fusion goal. SPARC is designed to hit Q>10, so in a way getting SPARC to Q>1 is like testing if your F1 race car can reach a speed of, say, 60 miles per hour.
https://blog.cfs.energy/why-cfs-is-confident-well-demonstrate-net-fusion-energy-q1/
