Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Not long after started playing, around 3 years ago, Hecarim was one of the first champions I bought. Since then I've played him off and on, and usually not doing bad but never really that good either. After watching a Pants Are Dragon (video), I was suddenly inspired to start playing him again. In the video, Pants tries different builds where you don't finish your jungle item and instead just build Phage. I've been trying it lately, and it's a ton of fun and I definitely think Hecarim is best if you get Tri-Force then finish your Cinderhulk.
Here's a screenshot of my past few games, all of the Hecarim games went pretty well.
I prefer using Flash over Ghost because Flash allows some better plays and outplays, vs Ghost just adding some extra damage and gap closing.
Thanks for looking and let me know what you think :)