Startup founders always consider how they can hold onto as much of the company as possible.  This usually means creating enough value in the company such that they don't have to sell a greater percentage of it per each dollar they accept from investors.  But, creating value usually requires investment.  So, either the founder goes down the traditional path, or he gets creative and creates value through different approaches.   Either way, the company has to survive long enough to begin selling something to the customer, or achieve certain milestones to be attractive to the acquiring company. 

Each horizontal section is a funding sequence.  Sequence "A" is the traditional angel-round, VC round process.  This is what every startup advisor will tell you is the way to go.  First, get the seed money from an Angel, build the initial proof of concept offering to prove that it works.  But, because you don't have it developed enough to sell to a customer, you need an A-round of venture investment to finish it.  Those that need substantial amounts of capital to gain traction in the market and become cashflow positive will cycle back through the last two steps.  Some founders will give away the whole company by the time they achieve positive cashflow, get acquired, or do an IPO. 

Sequence B is highly dependent upon the type of service or product.  If you can self-fund the commercial offering after you've built the prototype, or if the initial funding can take you to that level, you don't have to give away any more of the company.  If the product is captial-intensive, this is typically not an option. 

Sequence C is a creative way of financing the product by having a pre-existing customer willing to fund the development.   If the IP can be controlled, the founder can walk away with a valuable asset, while the customer can receive the value of the offering at a relatively reduced rate.  But, commercial products typcially require additional work after the initial development in order to make them solid and ready for general availability.  Additional investment will not be available from the initial customer, but the founder has momentum that he can demonstrate to investors.  While this may not be any easier to get funded than other great business models, all things being equal, this is a powerful story for investors. 

Sequence D is merely a shortened version of Sequence C.  A second round of investment is not required, therefore the founder can retain more of the company.

Sequence E is where the founder uses the profit generated from the initial engagement to develop the offering for the first customer to fund the remaining development.   If the offering doesn't require more than 1/2 of the funding for the proof of concept to cross the General Availability threshold, this will keep most of the value in the hands of the founder. 

Sequence F is where the offering can be developed without incurring any incremental cost for a prototype to placate the funding-customer.  No additional investment is required, and the company can be commercially-launched and start generating revenue. 

Sequence G is the self-funded, organically-developed process.   This is the opposite extreme of a funding strategy.  Typically, this is reserved for wealthy entrepreneurs who expose substantial wealth to the risks of a startup failure.  But, they get to keep it all and have few obligations to any funding-customer. 

Risk assessment cannot be consistently applied to these scenarios because the business model and environment will dictate differing levels of exposure to failure, and subsequently lower returns for the founder.  You have to rationally consider what is going to be required to take the offering over the finish line and get customers to start paying for it.  If it requires a lot of capital and you don't have it and you can't get a customer to fund it, then you are putting the entire concept at substantial risk by going down a path other than A or B.  Sometimes you have to move very quickly to be first to market, and capital can often speed up the development of an offering (but not always).  

Finally, the real goal should not be the percent ownership, but the absolute wealth created.   A small slice of a huge pie is always better than having the whole pie that doesn't exist.  If you can't get the startup over the finish line (customer revenue or acquisition), then you have zero.