What are the Odds? (WATO) can be very helpful for those investigating genealogical mysteries such as unknown parentage. WATO is a web application released in 2018 and based on concepts developed by Leah Larkin and documented in her series Science the heck out of your DNA.
In 2024, I released an overhauled version of WATO: WATO plus. In this short post, I’ll explain the main differences between these versions.
WATO vs WATO plus: the main differences:
- WATO plus asks for more specific information up front and is therefore able to make more useful suggestions.
- For example, while in the original WATO you just stated the birth year of the DNA tester, in the new version, you give the birth year of the person who has the unknown parent (this could be for example the parent, grandparent or other ancestor of the tester)
- If for example you state you’re looking for the unknown father of your mother Kathy, whenever you create a hypothesis, WATO plus will create a node for Kathy and a node for you.
- It will also only suggest males as candidates to be the unknown father
- In WATO plus, the Hypothesis is the person you think was the unknown parent
- In the original WATO, you added a hypothesis to each place where you thought the DNA tester might fit into the tree. This worked fine in unknown parentage cases, but got confusing for other scenarios such as unknown grandparents
- Scores are given as percentages in WATO plus
- Originally, the score was an absolute number. More info is available in the Scores section of the WATO plus FAQ.
- In WATO plus, you can take account of the age that a candidate to be their parent was at the time they were born.
- More info is available below under probabilities in the WATO plus FAQ.
- The default set of probabilities is different
- In both WATO and WATO plus you can switch between 2016 and 2020 (aka beta) probabilities. In WATO plus, the 2020 probabilities are the default.
- Read more in the FAQ.
WATO vs WATO plus: summary table showing the key differences
| WATO | WATO plus | |
| Who does the hypothesis represent? | The DNA tester | The person you think could have been the unknown parent |
| Scores | Numerical | Relative probability percentages |
| Age probabilities | Not considered | Can be factored into the calculation |
| Access | Free with DNA Painter account | One tree available free; subscription required for additional trees. |
| Default probabilities | 2016 | 2020 |
Further information
What are the Odds v3 sneak peek
Short video tutorial for WATO plus
Contact info: @dnapainter.bsky.social / jonny@dnapainter.com