Drawing from Sun Tzu and Charlie Munger, the key to long-term investment success is not brilliance in stock picking, but systematically avoiding common causes of failure. By identifying and steering clear of ruinous risks like excessive debt, leverage, and options, an investor is already in a superior position.

Howard Marks warns that during a downturn, private credit managers may avoid recognizing defaults by simply extending loan terms for struggling companies. This 'extend and pretend' strategy can mask underlying problems, keeping assets marked artificially high and delaying a painful reckoning for investors.

Identifying flawed investments, especially in opaque markets like private credit, is rarely about one decisive discovery. It involves assembling a 'mosaic' from many small pieces of information and red flags. This gradual build-up of evidence is what allows for an early, profitable exit before negatives become obvious to all.

This "via negativa" approach, inspired by Sun Tzu and Charlie Munger, posits that the easiest way to improve returns is by systematically avoiding common mistakes. Instead of trying to be brilliant, investors should focus on not doing "dumb stuff," as it's easier to identify what leads to failure than what guarantees success.

Oaktree's co-CEO highlights a critical flaw in applying venture logic to debt. In a diversified equity portfolio, one huge winner can offset many failures. In a diversified debt portfolio, the winner only pays its coupon, which is grossly insufficient to cover the principal losses from the losers.

A crucial, yet unquantifiable, component of alpha is avoiding catastrophic losses. Jeff Aronson points to spending years analyzing companies his firm ultimately passed on. While this discipline doesn't appear as a positive return on a performance sheet, the act of rigorously saying "no" is a real, though invisible, driver of long-term success.

In bond investing, where upside is capped at a promised return, superior performance comes from what you exclude, not what you buy. The primary task is to eliminate the bonds that will default. Once those are removed, all the remaining performing bonds deliver a similar, contractually-fixed return.

Goodwin argues against the passive "index-hugging" approach to credit focused on coupon payments and agency ratings. Diameter's edge comes from approaching credit like an equity long-short fund, constantly analyzing what macro and sector trends will change security prices over the next 3 to 24 months to generate total return.

In the current late-cycle, frothy environment, maintaining investment discipline is paramount. Oaktree, guided by Howard Marks' philosophy, is intentionally cautious and passing on the majority of deals presented. This discipline is crucial for avoiding the "worst deals done in the best of times" and preserving capital for future dislocations.