Tested this issue using latest Chrome version #58.0.3029.110 on Win 0. Unable to reproduce the issue. Could you please find the attached screen cast and let me know if I had missed any steps.

If possible please attach a expected Screen cast, that would expedite our triaging process.

Thanks, 

Deleted: May 29 2017 2-48 AM.webm 3.2 MB

	May 29 2017 2-48 AM.webm 3.2 MB View Download

Reasonable lines would be defined by the quality of the actual source map.

"Reasonable lines would be defined by the quality of the actual source map."

Both Firefox and IE11 do a better job of allowing breakpoints to be set than Chrome with the exact same .js, .ts, and .js.map files.  I thought since Google's Angular project is in Typescript that I would get first-class support for Typescript.  The source map is coming from the Typescript compiler.  Whose Typescript compiler should I be using then to get Chrome to be able to set breakpoints  basically anywhere like Firefox and IE11 can?  Right now, in my experience, it is like swiss cheese with holes all over the place where you are not allowed to select a breakpoint.  You select one line and then the developer tools selects a different line to place the breakpoint.  I don't understand how you guys would find this acceptable.  It would be one thing if the other browsers did just as poor of a job at this, but they both are significantly better.  That is ok with you guys?

https://www.screencast.com/t/OHNPFOtfPW

The above video shows what I am talking about while running the latest version of Chrome.