Ask HN: How do I deal with the "unpaid overtime crowd"?

The moment I step through my work door I set a timer for 7.5 hours. Once that timer is up, I close all my work, and go home. There are 4 people on my team, who I honestly think just do not have their own lives. They come in at 8am, and leave around 10. Every single day. I am at the bottom of our "scoreboard" for bug fixes, yet I work the most efficiently. They have 3x more fixes than I because they just choose to sit here for hours and hours and hours and just work, I don't get it. Now I look bad in comparison, management doesn't give a shit (obviously) and I have already had my job threatened. "I have no problem buying out the your contract, you're the least effective on our team". And "Why can't you be like _________ and __________?" My favourite part is, I designed the entire UI/UX for the app, I coded all of it for over 15 mobile devices. These people do not have the same skill set as I do. I explained everything to management,