Solid reference. I'm a course superintendent and I've bought divot tools on reputation and price for years without really understanding tine geometry or steel grades. This book fixed that. The chapter on maintenance is genuinely useful—I've already set up a sharpening station in our maintenance barn. Only reason it's not 5 stars: the business chapter is interesting but a bit thin on real numbers, like typical wholesale margins. But for the core content on choosing and using tools, it's the best I've read.